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  • 1.
    Abeywardana, Asela Janaka
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Solar - Biomass hybrid system for process heat supply in medium scale hotels in Sri Lanka2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This study aimed at evaluating and demonstrating the feasibility of using Concentrated Solar Thermal technology combined with biomass energy technology as a hybrid renewable energy system to supply the process heat requirements in small scale industries in Sri Lanka. Particularly, the focus was to apply the concept to the expanding hotel industry, for covering the thermal energy demand of a medium scale hotel.

    Solar modules utilize the rooftop area of the building to a valuable application. Linear Fresnel type of solar concentrator is selected considering the requirement of the application and the simplicity of fabrication and installation compared to other technologies. Subsequently, a wood-fired boiler is deployed as the steam generator as well as the balancing power source to recover the effects due to the seasonal variations in solar energy. Bioenergy, so far being the largest primary energy supply in the country, has a good potential for further growth in industrial applications like small hotels. 

    When a hotel with about 200-guests capacity and annual average occupancy of 65% is considered, the total annual CO2 saving is accounted as 207 tons compared with an entirely fossil fuel (diesel) fired boiler system. The annual operational cost saving is around $ 40,000 and the simple payback period is within 3-4 years. The proposed hybrid system can generate additional 26 employment opportunities in the proximity of the site location area.  

    This solar-biomass hybrid concept mitigates the weaknesses associated with these renewable technologies when employed separately. The system has been designed in such a way that the total heat demand of hot water and process steam supply is managed by renewable energy alone. It is thus a self-sustainable, non-conventional, renewable energy system. This concept can be stretched to other critical medium temperature applications like for example absorption refrigeration. The system is applicable to many other industries in the country where space requirement is available, solar irradiance is rich and a solid biomass supply is assured.    

  • 2.
    Ameen, Arman
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Efficient Cooling with multiple impinging jets: Obtaining boundary condition and verification for a CFD model2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Saving energy and optimizing industrial processes are major priorities for companies around the world. In this study the cooling process (with air) of large rollers are examined. The result of these examinations are used to create a computational fluid dynamic model. These examination consists of geometry, volume flows, velocities, velocity profiles, temperature and pressure. A complication in the measurements occurred due to the nonsymmetrical installation of the nozzles in the cooling setup. The results highlights how this nonsymmetrical installation affects the cooling. Multiple methods were used to carry out this work, and some additional side project were implemented. The results in this thesis is not enough to create a CFD model and further work have to be carried out in the future.

  • 3.
    Ameen, Arman
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Reducing energy usage in multi-family housing2019In: 2019 9th International Conference on Future Environment and Energy 9–11 January 2019, Osaka, Japan, Institute of Physics Publishing (IOPP), 2019, Vol. 257, article id 012030Conference paper (Refereed)
    Abstract [en]

    The energy usage in residential sector have been around 22% of the total energy use in the world and increasing due to the population growth and higher living standards. The energy sources for this are made up primarily of non-renewable energy resources which generates a large amount of global greenhouse gases. A lot of countries have implemented various regulations and rules to reduce the energy usage in buildings and promoting the use of renewable energy technologies. This paper presents a parametric study of a typical multi-family building in its pre-design stage. The climate location used is Sweden (Gothenburg) and Japan (Osaka). The aim of the study is to compare various configurations and to examine how they affect the energy use. The most interesting configurations are the use of heat pump and solar cells. Other configurations that are examined are infiltration levels, pressure coefficients, wind impact, ventilation with heat recovery, ventilation scheduling, building orientation and finally changing U-values in the building material. Results of this study show that the energy saving, by utilizing a heat pump and solar panels, can reduce the total energy use by 34.9% for Gothenburg and 32% for Osaka. The results also show that the difference in total energy use between the two cities reduce substantially (3% difference) when utilizing a heat pump in combination with solar panels.

  • 4.
    Ameen, Arman
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Larsson, Ulf
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Karimipanah, Taghi
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Experimental investigation of ventilation performance of different air distribution systems in an office environment – cooling mode2019In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 12, no 7, article id 1354Article in journal (Refereed)
    Abstract [en]

    The performance of a newly designed corner impinging jet air distribution method with an equilateral triangle cross section was evaluated experimentally and compared to that of two more traditional methods (mixing and displacement ventilation). At nine evenly chosen positions with four standard vertical points, air velocity, turbulence intensity, temperature, and tracer gas decay measurements were conducted for all systems. The results show that the new method behaves as a displacement ventilation system, with high air change effectiveness and stratified flow pattern and temperature field. Both local air change effectiveness and air exchange effectiveness of the corner impinging jet showed high quality and promising results, which is a good indicator of ventilation effectiveness. The results also indicate that there is a possibility to slightly lower the airflow rates for the new air distribution system, while still meeting the requirements for thermal comfort and indoor air quality, thereby reducing fan energy usage. The draught rate was also lower for corner impinging jet compared to the other tested air distribution methods. The findings of this research show that the corner impinging jet method can be used for office ventilation.

  • 5.
    Amiri, Shahnaz
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering.
    Possibilities and consequences of deregulation of the European electricity market for connection of heat sparse areas to district heating systems2010In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 87, no 7, p. 2401-2410Article in journal (Refereed)
    Abstract [en]

    The objective of the study is to analyse the conditions for connection of residential buildings in heat sparse areas to district heating systems in order to increase electricity production in municipal combined heat and power plants. The European electricity market has been assumed to be fully deregulated. The relation between connection of heat sparse areas, increased electricity and heat production as well as electricity prices, fuel prices and emissions rights is investigated. The results of the study show that there is potential to expand the district heating market to areas with lower heat concentrations in the cities of Gavle, Sandviken and Borlange in Sweden, with both economic and environmental benefits. The expansion provides a substantial heat demand of approximately 181 GWh/year, which results in an electricity power production of approximately 43 GWh/year. Since the detached and stand-alone houses in the studied heat sparse areas have been heated either by oil boiler or by direct electricity, connection to district heating also provides a substantial reduction in emissions of CO(2). The largest reductions in CO(2) emissions are found to be 211 ktonnes/year assuming coal-fired condensing power as marginal electricity production. Connection of heat sparse areas to district heating decrease the system costs and provide a profitability by approximately 22 million EURO/year for the studied municipalities if the price of electricity is at a European level, i.e. 110 EURO/MWh. Sensitivity analysis shows, among other things, that a strong relation exists between the price of electricity and the profitability of connecting heat sparse areas to district heating systems.

  • 6.
    Amiri, Shahnaz
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik. Department of Management and Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden.
    Trygg, Louise
    Department of Management and Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden.
    Moshfegh, Bahram
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik. Department of Management and Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden.
    Assessment of the natural gas potential for heat and power generation in the County of Östergötland in Sweden2009In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 37, no 2, p. 496-506Article in journal (Refereed)
    Abstract [en]

    The aim of this study is to investigate the potential use of natural gas for heat and power production for the municipality of Linkoping, Norrkoping and Finspang in the County of Ostergotland, Sweden. The results of the study revealed that these three municipalities with the present heating demand can convert 2030 GWh/year of the present fuel mixed to natural gas. The expansion of natural gas provides the possibility to increase the electricity generation with approximately 800 GWh annually in the County of Ostergotland. The global emissions of CO(2) reduce also by approximately 490 ktonne/year by assuming the coal condensing power plant as the marginal power plant. The total system cost decreases by 76 Mkr/year with the present electricity price which varies between 432 and 173 SEK/MWh and with 248 Mkr/year if the present electricity price increases to 37% which is approximately corresponding to European electricity prices. Sensitivity analysis is done with respect to the different factors such as price of electricity, natural gas, etc. The findings show that increased price of electricity and increased district heating demand increases the profitability to convert to natural gas using CHP plant. (C) 2008 Elsevier Ltd. All rights reserved.

  • 7.
    Andersen, Niklas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Wind Turbine End of Life: Characterisation of Waste Material2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Wind power is growing fast all over the world, and in Sweden alone thousands of turbines has been installed the last few decades. Although the number of decommissioned turbines so far is very low, the rapid installation rate indicates that a similar rapid decommissioning rate is to be expected shortly. If the waste material from these turbines is not handled sustainably the whole concept of wind power as a clean energy alternative is challenged.

    This study aims to present an accurate estimate of the amounts of waste material that will be generated from wind turbines in Sweden during the coming decades, allowing the waste management industry to plan for this and by extension prevent unnecessary energy losses through imperfect waste treatment. It should also present helpful information on how problematic waste can be reduced or avoided.

    VindStat’s annual report, presenting installation date and other relevant data for most installed turbines in Sweden, has been used as the base for the calculations. Information on material composition in different types and sizes of wind turbines has been extracted from various life cycle assessments, and by using the available parameters in the data base each turbine has been assigned a specific amount of steel, iron, copper, aluminum, blade material and electronics. An average life time of 20 years has been assumed, based on prior research and comparison with empiric data, and the material of each turbine is therefore seen as generated waste 20 years after installation date.

    To calculate the amount of waste material from replacing faulty components, empiric data over replacement rates in further developed markets has been combined with a prognosis over future development of installed wind capacity in Sweden based on a method described by prior research. As no sufficient way to predict how the future second hand market for turbines and components has been found, three different possible scenarios have been investigated to see how this may affect waste amounts.

    The results show that annual waste will grow slowly at about 12 % increase per year until around 2026, and then the average increase is 41 % per year until 2034. By then, annual waste amounts are estimated to have reached 237 600 tonne steel and iron (16 % of currently recycled amounts), 2 300 tonne aluminium (4 %), 3 300 tonne copper (5 %), 343 tonne electronics (<1 %) and 28 100 tonne blade material. There is no industrial scale recycling method for commonly used blade materials, and a high strength steel developed by Sandvik is proposed as a fully recyclable material to consider for further research. A well-functioning second hand market is shown to possibly have a major impact on waste amounts, at least in postponing it until better recycling systems are in place.

  • 8.
    Andersson, Harald
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Numerical and experimental study of confluent jets supply device with variable airflow2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In recent years, application of confluent jets for design of ventilation supply devices has been studied. Similarly, numerus studies have been made on the potential and application of variable air volume (VAV) in order to reduce the energy demand of ventilation systems. This study investigates the combination of supply devices based on confluent jets and VAV, both in terms of the nearfield flow behavior of the device and the impact on thermal comfort, indoor air quality and energy efficiency on a classroom-level space when the airflow rate is varied.

    The method used in this study is an experimental field study where the confluent jets-based supply devices were compared to the previously installed displacement ventilation. The field study evaluated the energy efficiency, thermal comfort and indoor air quality of the two systems. In the case of the confluent jets supply devices, airflow rate was varied in order to see what impact the variation had on the performance of the system for each airflow rate. Furthermore, the confluent jets supply devices were investigated both experimentally and numerically in a well insulated test room to get high resolution data on the particular flow characteristics for this type of supply device when the airflow rate is varied. The results from the field study show nearly uniform distribution of the local mean age of air in the occupied zone, even in the cases of relatively low airflow rates. The airflow rates have no significant effect on the degree of mixing. The thermal comfort in the classroom was increased when the airflow rate was adapted to the heat load compared to the displacement system. The results lead to the conclusion that the combination of supply devices based on confluent jets can reduce energy usage in the school while maintaining indoor air quality and increasing the thermal comfort in the occupied zone.

    The results from the experimental and numerical study show that the flow pattern and velocity in each nozzle is directly dependent on the total airflow rate. However, the flow pattern does not vary between the three different airflow rates. The numerical investigation shows that velocity profiles for each nozzle have the same pattern regardless of the airflow rate, but the magnitude of the velocity profile increases as the airflow increases. Thus, a supply device of this kind could be used for variable air volume and produce confluent jets for different airflow rates.

    The results from both studies show that the airflow rate does not affect the distribution of the airflow on both near-field and room level. The distribution of air is nearly uniform in the case of the near-field results and the room-level measurement shows a completely uniform degree of mixing and air quality in the occupied zone for each airflow rate. This means that there is potential for combining these two schemes for designing air distribution systems with high energy efficiency and high thermal comfort and indoor air quality.

  • 9.
    Andersson, Harald
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Experimental and numerical investigations of a new ventilation supply device based on confluent jets2018In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 137, p. 18-33Article in journal (Refereed)
    Abstract [en]

    In developed countries, heating, ventilation, air conditioning (HVAC) systems account for more than 10% of national energy use. The primary function of a HVAC system is to create proper indoor environment. A number of ventilation strategies have been developed to minimize HVAC systems’ energy use whilst still maintaining a good indoor environment. Among these strategies are confluent jet ventilation and variable air volume. In this study, an air supply device with a novel nozzle design that uses both of the above-mentioned strategies was investigated both experimentally and numerically at three different airflow rates. The results from the numerical investigation using the SST k - ω turbulence model regarding velocities and flow patterns are validated by experimental data carried out by Laser Doppler Anemometry. The results from both studies show that the flow pattern and velocity in each nozzle is directly dependent on the total airflow rate. However, the flow pattern does not vary between the three different airflow rates. The numerical investigation shows that velocity profiles for each nozzle have the same pattern regardless of the airflow rate, but the magnitude of the velocity profile increases as the airflow increases. Thus, a supply device of this kind could be used for variable air volume and produce confluent jets for the airflow rates investigated.

  • 10.
    Andersson, Niklas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Energieffektivisering av byggnad med enkla medel: en fallstudie på Hofors mödravårdscentral2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the central parts of Hofors a healthcenter is located which is included in Hoforshus AB's building stock, the building itself is divided into a main building and a smaller one in which the child health center and maternity care is located. The buildings are connected by a corridor substantially glazed. Now they are interested in maping the building's energyusage as this is relatively high, in addition, the users of the building had been dissatisfied with the indoor climate in both summer and winter. Because of the healtcare activities the owners were most interested in finding solutions that would not interfere with it.

    The study conducted has had a primary focus on the building envelope and above all on the glazed corridor’s impact on the rest of the building. One can assume that the high proportion of glass in this part of the building affects the indoor climate negatively keeping in mind the low U-value of the glass and the solar heat load, this gives during the summer when heat gain is not desired. A literature study to investigate how people perceive the climate as well as how to make a reliable simulation model of a building has been completed. The study resulted in an understanding of how the indoor climate is perceived and quantified, and also in an understanding of what is important in the collection of data for the simulation model.

    Keeping in mind how data should be collected according to the literature reviwe- have as much data as possible measured through surveys and own observations, blueprints have been studied and their validity has been investigated by measuring the building, blower door has been performed and temperature- and relative humidityloggning. Instantaneous values of the FTX system was made to calculate its efficiency. Linear thermal bridges have been investigated by finite element method in the program COMSOL Multiphysics 3.5. For validation of the simulated model the results of it were compared with the acutal measured energyconsumption of the building. The simulations were performed in BV2.

    The results of the study show, as expected, the glazed corridor’s negative impact on the building's indoor climate. Temperature was logged between 160412-160509 highest temperature was 30 ° C and minimum 15 ° C, which is more widespread than in other areas where the temperature was logged. The simulations that were performed on the glazed corridor shows that it consumes between 5000-5500 kWh on the area of 13.5 m2. Finally the study resulted in recommendations for the building that includes additional insulation of the attic, replacement of a smaller wall section, lowering the temperature by 1 ° C, as well as some maintenance measures to improve the indoor climate. The measures are believed to be possible to implement without significant interference with the health care acitivities. In addition the proposed measures seem profitable according to the pay of method.

  • 11.
    Angele, Kristian
    et al.
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering. Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Högström, Carl-Maikel
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Odemark, Ylva
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Henriksson, Mats
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Tinoco, Hernan
    Forsmarks Kraftgrupp AB, Östhammar, Sweden.
    Lindqvist, Hans
    Forsmarks Kraftgrupp AB, Östhammar, Sweden.
    Hemström, Bengt
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Flow Mixing Inside a Control-Rod Guide Tube: Part 2—Experimental Tests and CFD-Simulations2010In: 18th International Conference on Nuclear Engineering: Volume 4, Parts A and B, 2010, p. 655-663Conference paper (Refereed)
    Abstract [en]

    Alarge number of control rod cracks were detected during therefuelling outage of the twin reactors Oskarshamn 3 and Forsmark3 in the fall of 2008. The extensive damage investigationfinally lead to the restart of both reactors at theend of 2008 under the condition that further studies wouldbe conducted in order to clarify all remaining matters. Also,all control rods were inserted 14% in order to locatethe welding region of the control rod stem away fromthe thermal mixing region of the flow. Unfortunately, this measureled to new cracks a few months later due toa combination of surface finish of the new stems andthe changed flow conditions after the partial insertion of thecontrol rods. The experimental evidence reported here shows an increasein the extension of the mixing region and in theintensity of the thermal fluctuations. As a part of thecomplementary work associated with the restart of the reactors, andto verify the CFD simulations, experimental work of the flowin the annular region formed by the guide tube andcontrol rod stem was carried out. Two full-scale setups weredeveloped, one in a Plexiglass model at atmospheric conditions (inorder to be able to visualize the mixing process) andone in a steel model to allow for a highertemperature difference and heating of the control rod guide tube.The experimental results corroborate the general information obtained through CFDsimulations, namely that the mixing region between the cold crud-removalflow and warm by-pass flow is perturbed by flow structurescoming from above. The process is characterized by low frequent,high amplitude temperature fluctuations. The process is basically hydrodynamic, causedby the downward transport of flow structures originated at theupper bypass inlets. The damping thermal effects through buoyancy isof secondary importance, as also the scaling analysis shows, howevera slight damping of the temperature fluctuations can be seendue to natural convection due to a pre-heating of thecold crud-removal flow. The comparison between numerical and experimental resultsshows a rather good agreement, indicating that experiments with plantconditions are not necessary since, through the existing scaling lawsand CFD-calculations, the obtained results may be extrapolated to plantconditions. The problem of conjugate heat transfer has not yetbeen addressed experimentally since complex and difficult measurements of theheat transfer have to be carried out. This type ofmeasurements constitutes one of the main challenges to be dealtwith in the future work.

  • 12.
    Angele, Kristian
    et al.
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Odemark, Ylva
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering. Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Hemström, Bengt
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Högström, Carl-Maikel
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Henriksson, Mats
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Tinoco, Hernan
    Forsmarks Kraftgrupp AB, Östhammar, Sweden.
    Lindqvist, Hans
    Forsmarks Kraftgrupp AB, Östhammar, Sweden.
    Flow mixing inside a control-rod guide tube: Experimental tests and CFD simulations2011In: Nuclear Engineering and Design, ISSN 0029-5493, E-ISSN 1872-759X, Vol. 241, no 12, p. 4803-4812Article in journal (Refereed)
  • 13.
    Apell, Oscar
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Energikartläggning av Fridhemsskolan 16:22014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Increased energy consumption in the world has created an increased supply of various fuels, especially fossil fuels. The Swedish government has set up various energy targets for 2020. To reach these goals it’s important to increase the energy efficiency in local buildings such as schools. This work illustrates the breakdown between energy supply and energy losses over the school. It also shows various suggestions to reduce the energy usage. The results shows that energy losses from transmission is definitely the greatest. Significant savings can be made by replacing windows, add insulation and install motion sensor lightning. If the proposed savings would be made, the energy consumption of the school could decrease by approximately 165MWh/year. This represent an annual saving of about 123600 SEK.

  • 14.
    Arfan, Muhammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science. 202100-2890.
    Biogas Value Chain in Gävleborg: Feedstock, Production and Use2019Report (Other academic)
    Abstract [en]

    This report aims to identify the current status and future opportunities for biogas as an alternative fuel for road transport in the Gävleborg region. The regional actors along the value chain are mapped by their role in feedstock supply, production and use of the biogas. Mapping and analysis of biogas development generally in Sweden and particularly in the Gävleborg region has been conducted primarily through literature, national and regional statistics and through interviews with the regional actors. About 15 companies were reached through emails and phone calls during the interview process.

    In 2017, about 3.5-4.0 million Nm3 of raw biogas (50-65% CH4) was produced in the region of which 3.6 GWh was upgraded. The region has two plants with upgrading facilities, one in Forsbacka, which produces gas mainly from food waste and Duvbacken, the wastewater treatment plant in Gävle. The gas produced at these two big facilities is upgraded and mostly used as transport fuel in the region, and for the industry. Gas produced from other sources is either used for heat and electricity production or flared to avoid methane emissions to the environment. The region has 14 buses and more than 500 other vehicles running on biogas. The gas infrastructure is not well developed in the region except for two filling stations situated in Gävle and Forsbacka. However, some developments on building biogas infrastructure for transport are in process.

    Analysis of interviews with actors and literature studies revealed that the region has much more feedstock for biogas production than used in the currently installed capacity of biogas technologies. Many actors showed great interest in its use as transport fuel but had very serious concerns about its future scope. Lack of supporting infrastructure such as filling stations, very low market demand and regional long-term strategies on biogas as transport fuel are considered barriers in the sector´s further development in the region. The value chain actors need to work more closely to get the most out of this valuable resource. Additionally, future planning on biogas should also consider its other uses such as an energy source for manufacturing industry, shipping and as raw material for chemicals or intermediate products.

  • 15.
    Arizcun Zúñiga, Paula María
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Ram pump hydraulic air test. Pressure conditions and flow measurements: Experimental research and case study2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study consists of the development of a ram pump, which will allow the pumping of water without the need of external energy sources. It is considered an analysis of interest since, once it is finished; it can be applied in reality improving and facilitating different activities related to agriculture and health.

    Previous studies have been made related to the ram pump; however, in this case, it is intended to understand the system that has been built in the laboratory in order to find the best combination of parameters that will lead to obtain the highest possible efficiency. 

    The study will be carried out by studying scientific literature and by experimenting in the laboratory. Encompassing the experimental and literary field, it is expected to understand perfectly the advantages and disadvantages of the ram pump in order to determine if it is worth it to install in certain places.

    After the study, the most favourable parameters for the operation of the Bruzaholms Bruk pump have been obtained. It has been found that the use of a longer drive pipe favours the operation of the system, as it is possible to obtain a higher efficiency, although it must be taken into account that the mentioned length needs to be controlled, as it could reduce the working rhythm of the pump. It has also been seen that the pump gives better results if the impulse valve is completely opened. Finally, it has been proven that, as long as the height difference between the two tanks is enough, increasing the height of the water source will favour the operation of the system.

  • 16.
    Arnfelt, Emma
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    En byggnads energiprestanda: En utredande och jämförande studie av Boverkets författningssamling BEN12017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is an exploratory and comparative study of Boverkets constitution BEN1. In this study the constitution BEN1 is examined, why the constitution was established, when is it applicable and what advantages and disadvantages will come with it. Today the housing and service sector is using a major part of Europe’s final energy use, in addition to this, these sectors also represents a major part of the total carbon dioxide emissions. The EU-commission aims to reduce the housing and service sectors energy use and emissions. In 2002 the European parliament established directives and demands for buildings energy performance. These directives were changed in 2009-2010, which led to an inspection of the already existing Swedish constitution, this was found to be inadequate by the EU-commission. Sweden decided to create a new constitution in order to satisfy EU’s new directives and demands. The focus is on a normal usage of the building in a normal year in the new constitution, BEN1. 

    The reader should receive an idea and understanding about BEN1 and why it was established in this report. Beyond this, the study will show the changes that happen to a buildings energy performance after the constitution is applied and what advantages and disadvantages this could bring. 

    This study was performed by simulating the buildings energy use with the input from BEN1 in a simulation tool, IDA Indoor Climate and Energy. 

    The study shows that the energy performance will change but it also shows that further studies should be made in order to obtain a more carefully drawn and common conclusion.

  • 17.
    Arushanyan, Yevgeniya
    et al.
    Division of Environmental Strategies Research, Department of Sustainable development, Environmental Science and Engineering, School of Architecture and Built Environment, KTH Royal Institute of Technology, Stockholm, Sweden.
    Bjorklund, Anna
    Division of Environmental Strategies Research, Department of Sustainable development, Environmental Science and Engineering, School of Architecture and Built Environment, KTH Royal Institute of Technology, Stockholm, Sweden.
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Finnveden, Göran
    Division of Environmental Strategies Research, Department of Sustainable development, Environmental Science and Engineering, School of Architecture and Built Environment, KTH Royal Institute of Technology, Stockholm, Sweden.
    Soderman, Maria Ljunggren
    Division of Environmental Systems Analysis, Department of Energy and Environment, Chalmers University of Technology, Göteborg, Sweden.
    Sundqvist, Jan-Olov
    IVL Swedish Environmental Research Institute, Stockholm, Sweden.
    Stenmarck, Åsa
    IVL Swedish Environmental Research Institute, Stockholm, Sweden.
    Environmental Assessment of Possible Future Waste Management Scenarios2017In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 10, no 2, article id 247Article in journal (Refereed)
    Abstract [en]

    Waste management has developed in many countries and will continue to do so. Changes towards increased recovery of resources in order to meet climate targets and for society to transition to a circular economy are important driving forces. Scenarios are important tools for planning and assessing possible future developments and policies. This paper presents a comprehensive life cycle assessment (LCA) model for environmental assessments of scenarios and waste management policy instruments. It is unique by including almost all waste flows in a country and also allow for including waste prevention. The results show that the environmental impacts from future waste management scenarios in Sweden can differ a lot. Waste management will continue to contribute with environmental benefits, but less so in the more sustainable future scenarios, since the surrounding energy and transportation systems will be less polluting and also because less waste will be produced. Valuation results indicate that climate change, human toxicity and resource depletion are the most important environmental impact categories for the Swedish waste management system. Emissions of fossil CO2 from waste incineration will continue to be a major source of environmental impacts in these scenarios. The model is used for analyzing environmental impacts of several policy instruments including weight based collection fee, incineration tax, a resource tax and inclusion of waste in a green electricity certification system. The effect of the studied policy instruments in isolation are in most cases limited, suggesting that stronger policy instruments as well as combinations are necessary to reach policy goals as set out in for example the EU action plan on circular economy.

  • 18.
    Assefa, Getachew
    et al.
    Avdelningen för industriellt miljöskydd, KTH, Stockholm.
    Eriksson, Ola
    Avdelningen för industriellt miljöskydd, KTH, Stockholm.
    Frostell, Björn
    Avdelningen för industriellt miljöskydd, KTH, Stockholm.
    Kuttainen, Karin
    Avdelningen för industriellt miljöskydd, KTH, Stockholm.
    Kompostering eller förbränning av hushållsavfall i Stockholm: En systemstudie av effekter på miljö, energi och ekonomi2001Report (Other academic)
    Abstract [sv]

    En systemanalys som utvärderar potentiella effekter på miljön, energiomsättning och ekonomi har genomförts där storskalig kompostering jämförts med förbränning. Studien har utförts på uppdrag av Birka Värme och är tänkt som en jämförelse av olika former av kapacitetsökning för behandling av avfall i Stockholmsområdet. Förebilder för behandlingsprocesserna är avfallsförbränningsanläggningen Högdalenverket som drivs av Birka Energi och en planerad storskalig komposteringsanläggning i Stora Vika i Rondecos regi. Avfallet samlas in från Stockholm med närområden. Avfallet består till större delen av lättnedbrytbart organiskt avfall och slam från reningsverk. Även rötning har jämförts där en mindre del av totala avfallet, motsvarande ledig kapacitet i rötningsanläggningen, behandlas.

    Studien visar att det ur de flesta av de betraktade aspekterna är fördelaktigare att förbränna avfallet än att kompostera det. Detta beror på miljöpåverkan (övergödning och höga tungmetallhalter) i hanteringen av kompostpelletsen och inverkan av att förlorad fjärrvärmeproduktion vid kompostering måste ersättas.

    Kompostering är att föredra ur klimatsynpunkt då dess bidrag till global uppvärmning (växthuseffekten) är totalt sett något lägre än för förbränning. Det beror till största del på att koldioxid från förbränning av plast som finns i avfallet frigörs vid avfallsförbränningen. Skillnaden är dock inom felmarginalen och resultatet bör ej tas för självklart.

    För den potentiella miljöeffekten försurning är det dött lopp mellan kompostering och förbränning. Förbränningen av avfall ger visserligen högre försurande utsläpp än komposteringen men när hänsyn tas till att förlorad fjärrvärme måste ersättas vid kompostering och att det går åt mer elektricitet vid kompostering, elektricitet som antas framställas från förbränning av kol, jämnar resultatet ut sig.

    Det finns en hel del svagheter i analysen, bland annat är det inte fullständigt klarlagt vilka materialbalanser som råder i komposteringsprocessen. Även för spridningen av kompostpelletsen råder stora osäkerheter. I dessa fall har antaganden gjorts men det är viktigt att i den fortsatta granskningen använda tillförlitligare data.

  • 19.
    Assefa, Getachew
    et al.
    Industrial Ecology, KTH Royal Institute of Technology, Stockholm, Sweden.
    Eriksson, Ola
    Industrial Ecology, Royal Institute of Technology (KTH),.
    Järås, Sven
    Chemical Technology, KTH Royal Institute of Technology, Stockholm, Sweden.
    Kusar, Henrik
    Chemical Technology, KTH Royal Institute of Technology, Stockholm, Sweden.
    Life Cycle Assessment of Thermal Treatment Technologies: An environmental and financial systems analysis of gasification, incineration and landfilling of waste2002Report (Other academic)
    Abstract [en]

    A technology which is currently developed by researchers at KTH is catalytic combustion which is one component of a gasification system. Instead of performing the combustion in the gas turbine by a flame, a catalyst is used. When the development of a new technology (as catalytic combustion) reaches a certain step where it is possible to quantify material-, energy- and capital flows, the prerequisites for performing a systems analysis is at hand. The systems analysis can be used to expand the know-how about the potential advantages of the catalytic combustion technology by highlighting its function as a component of a larger system. In this way it may be possible to point out weak points which have to be investigated more, but also strong points to emphasise the importance of further development.

    The aim of this project was to assess the energy turnover as well as the potential environmental impacts and economic costs of thermal treatment technologies in general and catalytic combustion in particular. By using a holistic assessment of the advantages and disadvantages of catalytic combustion of waste it was possible to identify the strengths and weaknesses of the technology under different conditions. Following different treatment scenarios have been studied: (1) Gasification with catalytic combustion, (2) Gasification with flame combustion, (3) Incineration with energy recovery and (4) Landfilling with gas collection. In the study compensatory district heating is produced by combustion of biofuel. The power used for running the processes in the scenarios is supplied by the waste-to-energy technologies themselves while compensatory power is assumed to be produced from natural gas. The emissions from the system studied were classified and characterised using methodology from Life Cycle Assessment into the following environmental impact categories: Global Warming Potential (also called the green house effect), Acidification Potential, Eutrophication Potential and finally Formation of Photochemical Oxidants.

    It is obvious that a decreased use of landfilling in favour of an increased energy recovery from waste is positive from all considered impact categories. Gasification with energy recovery in a combi cycle using catalytic combustion in the gas turbine is the most competitive technology from primarily an environmental point of view. The financial costs are however a bit higher than for incineration with energy recovery. This conclusion depends, however, on the assumption that the gasification and catalyst technologies work as the researchers presume and that the fuel is of high quality. For this, the pelletising unit is vital in the technology chain.

    A comparison of the catalytic combustion and the flame combustion shows that all impact categories except acidification, eutrophication and photochemical oxidants remain the same. The gasification process is identical between the two alternatives; it is just the combustion technology in the gas turbine that is different. This explains why the fuel consumption and the financial costs are not changed (a minor extra investment is made for the catalyst but is not noticeable in comparison to the total impact). Emissions of greenhouse gases are also identical. For the other impact categories there are differences for several of the emissions involved in the impact assessment but NOX is clearly the dominating one.

    Gasification with catalytic combustion is competitive to incineration. The small difference for eutrophication is within the error margin and is strongly dependent on the reduction of NOX in the incineration plant. The explanation to this result is that a combi cycle in combination with natural gas as the alternative power generation is a better system solution than incineration with biofuel as compensatory fuel. Financial costs are somewhat higher than for incineration but could also claimed to be within the error margin since the inventory of costs are more uncertain due to the fact that there is no plant with gasification and catalytic combustion in operation.

  • 20.
    Baky, Andras
    et al.
    Swedish Institute of Agricultural Environmental Engineering (JTI), Uppsala, Sweden.
    Eriksson, Ola
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Systems Analysis of Organic Waste Management in Denmark: Environmental Project No. 822 2003 Miljøprojekt2003Report (Other academic)
  • 21. Bisaillon, Mattias
    et al.
    Haraldsson, Mårten
    Sundberg, Johan
    Eriksson, Ola
    Systemstudie Avfall - Borås: En systemstudie för den framtida avfallsbehandlingen i Borås: Ett delprojekt inom projektet "Termisk och biologisk avfallsbehandling i ett systemperspektiv"2015Report (Other academic)
  • 22. Bisaillon, Mattias
    et al.
    Sundberg, J.
    Haraldsson, M.
    Eriksson, Ola
    Termisk och biologisk avfallsbehandling i ett systemperspektiv: Etapp 12009Report (Other academic)
  • 23.
    Blackman, Corey
    Högskolan Dalarna.
    Evaluation of a thermally driven heat pump for solar heating and cooling applications2015Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Exploiting solar energy technology for both heating and cooling purposes has the potential of meeting an appreciable portion of the energy demand in buildings throughout the year. By developing an integrated, multi-purpose solar energy system, that can operate all twelve months of the year, a high utilisation factor can be achieved which translates to more economical systems. However, there are still some techno-economic barriers to the general commercialisation and market penetration of such technologies. These are associated with high system and installation costs, significant system complexity, and lack of knowledge of system implementation and expected performance. A sorption heat pump module that can be integrated directly into a solar thermal collector has thus been developed in order to tackle the aforementioned market barriers. This has been designed for the development of cost-effective pre-engineered solar energy system kits that can provide both heating and cooling.

    This thesis summarises the characterisation studies of the operation of individual sorption modules, sorption module integrated solar collectors and a full solar heating and cooling system employing sorption module integrated collectors. Key performance indicators for the individual sorption modules showed cooling delivery for 6 hours at an average power of 40 W and a temperature lift of 21°C. Upon integration of the sorption modules into a solar collector, measured solar radiation energy to cooling energy conversion efficiencies (solar cooling COP) were between 0.10 and 0.25 with average cooling powers between 90 and 200 W/m2 collector aperture area. Further investigations of the sorption module integrated collectors implementation in a full solar heating and cooling system yielded electrical cooling COP ranging from 1.7 to 12.6 with an average of 10.6 for the test period.

    Additionally, simulations were performed to determine system energy and cost saving potential for various system sizes over a full year of operation for a 140 m2 single-family dwelling located in Madrid, Spain. Simulations yielded an annual solar fraction of 42% and potential cost savings of €386 per annum for a solar heating and cooling installation employing 20m2 of sorption integrated collectors.

  • 24.
    Bosnjak, Vjekoslav
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Waste Heat Recovery in Intensive Small and Medium Sized Industries: Case Study - Gästrike Härdverkstad2012Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In order to keep a high level and to stay competitive in the world market in the future, it is important for the Swedish steel industry to improve their efficiencies continuously and to reduce the energy consumption. In order to realize these goals, the Swedish steel association Jernkotoret was found and by their initiative Triple Steelix was found in 2006 in Berglanden, a significant area for the steel industry. In 2009, the Clean Production Centre was found in Hofors in order to build a cluster of local steel manufacturers, factories and companies. One of those companies is Gästrike Härdverkstad, a small steal heat treatment industry with six employees and about 700.000 tons treated materials every year.

    The aim for this thesis is to suggest solutions for recovering waste heat and lowering the total energy consumption in furnaces for heat treatment in the case of Gästrike Härdverkstad.

    Some limitations were necessary to complete the analysis and to come to conclusions. The yearly treated material and energy prices were assumed to be constant and the yearly power consumption was estimated by an extrapolation of a one to five days measurement.

    Gästrike Härdverkstad is located in Uhrfors, the southern part of Åshammar, a village with 727 inhabitants. There are not any buildings with a possibility to supply heat and there is no district heating in the surroundings. The company has a power consumption of 1.40 GWh/year, of which 65.7% is consumed by the 12 main furnaces. The rest is used by eight seldom used furnaces, devices and auxiliary machines of the support process like fans, pumps, compressor, office heating, and some other. The efficiencies of the main furnaces are between 10% and 20%.The estimated energy consumption of the space heating is about 27 MWh/year, which completely can be covered by the material coolant and the combustion heat of the exhaust gases from the hardening furnaces. Since there are 10 different types of furnaces with different duties and efficiencies, the preheating furnace was taken as an example and compared with a new furnace. According to the needs of Gästrike Härdverkstad, the furnace VAW 60/100-650°C from the company Vötsch was chosen at the cost of 248,827 SEK. The payback time depends on the efficiency. With an efficiency of 40% the payback time would be about 13 years, see Figure 20.

    After the annealing and ageing, the finished products are cooled down in the building hall by the ambient air. In future, the possibility of preheating the material with the heat of the finished products should be considered. With an efficiency of 30.87%, one preheating furnace could bereplaced, and taken a payback time of 5 years into account; the price of the construction would be allowed to be up to 253,200 SEK.

  • 25.
    Bravo Jimenez, Ismael
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Detection and removal of wind turbine ice: Method review and a CFD simulation test2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Nowadays, the energy sector is facing a huge demand that needs to be covered. Wind energy is one of the most promising energy resources as it is free from pollution, clean and probably will arise as one of the main energy sources to prevent global warming from happening. Almost 10% of the global energy demand is coming from renewable resources. By 2050 this percentage is expected to grow to 60%. Therefore, efforts on wind turbine technology (i.e. reliability, design…) need to be coped with this growth.

    Currently, large wind energy projects are usually carried out in higher altitudes and cold climates. This is because almost all of the cold climates worldwide offer profitable wind power resources and great wind energy potential. Operating with wind turbines in cold climates bring interesting advantages as a result of higher air density and consequently stronger winds (wind power is around 10% higher in the Nordic regions). Not only benefits can be obtained but extreme conditions force to follow harsh conditions. Low temperatures and ice accretion present an important issue to solve as can cause several problems in fatigue loads, the balance of the rotor and aerodynamics, safety risks, turbine performance, among others. As wind energy is growing steadily on icy climates is crucial that wind turbines can be managed efficiently and harmlessly during the time they operate.

    The collected data for the ice detection, de-icing and anti-icing systems parts was obtained through the company Arvato Bertelsmann and is also based on scientific papers. In addition, computer simulations were performed, involving the creation of a wind tunnel under certain conditions in order to be able to carry out the simulations (1st at 0ºC, 2nd at -10ºC) with the turbine blades rotating in cold regions as a standard operation.

    In this project, Computational Fluids Dynamics (CFD) simulation on a 5MW wind turbine prototype with ice accretion on the blades to study how CL and CD can change, also different measures of ice detection, deicing and anti-icing systems for avoiding ice accumulation will be discussed. Simulation results showed a logical correlation as expected, increasing the drag force about 5.7% and lowering the lift force 17,5% thus worsening the turbine's efficiency.

  • 26. Brinkworth, BJ
    et al.
    Sandberg, Mats
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för inomhusmiljö.
    Design procedure for cooling ducts to minimise efficiency loss due to temperature rise in PV arrays2006In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 80, no 1, p. 89-103Article in journal (Refereed)
    Abstract [en]

    The principal variable to be fixed in the design of a PV cooling duct is its depth, and hence the hydraulic diameter of its cross-section D. Analysis of the flow and heat transfer in the duct under still-air (buoyant flow) conditions, when the temperature rise is greatest, is validated by measurements on a full-scale test rig. It is shown that there is an optimum value of this design variable, such that for an array of length L the minimum temperature occurs when the ratio L/D is about 20. The optimum value is not affected much by other quantities, including the slope of the array.

    In practical situations, the flow is obstructed by devices across the duct inlet and outlet to exclude insects, birds and rain, and by structural support members crossing the duct interior. It is shown that the latter are no cause for concern, since the effect of the reduction in the flow-rate due to their presence is more than offset by an increase in heat transfer through additional turbulent mixing.

    It is also shown that array temperatures are strongly reduced by wind effects, which increase both the heat lost from the front surface of the array and by enhancement of the flow in the duct. Though the trends are clear, limitations are encountered in the present state of knowledge in both areas. (c) 2005 Elsevier Ltd. All rights reserved.

  • 27. Broberg Viklund, Sarah
    et al.
    Johansson, Maria T.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Technologies for utilization of industrial excess heat: Potentials for energy recovery and CO2 emission reduction2014In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 77, p. 369-379Article in journal (Refereed)
    Abstract [en]

    Industrial excess heat is a large untapped resource, for which there is potential for external use, which would create benefits for industry and society. Use of excess heat can provide a way to reduce the use of primary energy and to contribute to global CO2 mitigation. The aim of this paper is to present different measures for the recovery and utilization of industrial excess heat and to investigate how the development of the future energy market can affect which heat utilization measure would contribute the most to global CO2 emissions mitigation. Excess heat recovery is put into a context by applying some of the excess heat recovery measures to the untapped excess heat potential in Gavleborg County in Sweden. Two different cases for excess heat recovery are studied: heat delivery to a district heating system and heat-driven electricity generation. To investigate the impact of excess heat recovery on global CO2 emissions, six consistent future energy market scenarios were used. Approximately 0.8 TWh/year of industrial excess heat in Gavleborg County is not used today. The results show that with the proposed recovery measures approximately 91 GWh/year of district heating, or 25 GWh/year of electricity, could be supplied from this heat. Electricity generation would result in reduced global CO2 emissions in all of the analyzed scenarios, while heat delivery to a DH system based on combined heat and power production from biomass would result in increased global CO2 emissions when the CO2 emission charge is low. 

  • 28.
    Broström, Simon
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Energianalys av byggnad i industriell miljö: Energikartläggning med effektiviseringsförslag till byggnad innehå̊llande betningsprocess hos Ovako Hofors AB2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Världen står inför stora utmaningar där energibehovet ständigt ökar i takt med den globala ekonomin. Något de flesta människor idag känner till är kopplingen mellan energianvändning och negativ påverkan av miljö samt klimat.

    Sveriges industrier står inför stora utmaningar med ständigt växande global marknad. Följder blir tuffare konkurrenssituation för många företag. Konkurrenssituationen medför att företag flyttar sin verksamhet till länder med lägre produktionskostnader. Kostnader vilka i Sverige har ökat väldigt mycket de senaste decennierna. För att stoppa utflyttning av industriverksamhet krävs stora effektiviseringar i industriföretags energianvändning och förändring av attityd gentemot energianvändning.

    Studien vilken ligger till grund för rapporten utfördes med energikartläggning av en lokal hos ståltillverkaren Ovako Sweden AB i Hofors. Lokalen där energikartläggningen utförts innehåller en process kallad betning. Kartläggningen grundas på data erhållna av ÅF, vilka även har varit samarbetspartners i studien.

    Väldigt stora mängder energi används i lokalen, närmare bestämt 14 000 MWh. Störst andel energi går till produktionsprocesser i form av ånga och elektricitet. Ånganvändning står för 8 500 MWh medan elektricitetsanvändning uppgår till 4 500 GWh. För ånga kan kostnadsminskning med 60 % implementeras. Elektricitetskostnader kan med föreslagna metoder minskas med uppskattningsvis 14 %.

    För uppvärmning av lokalen beräknades användningen uppgå till 2 500 MWh. Användning av uppvärmningsenergi kan minskas drastiskt då byggnaden är väldigt dåligt isolerad och använder mycket energi till uppvärmning. Vid införande av samtliga föreslagna åtgärder för uppvärmning sparas totalt 95 % av uppvärmningskostnader 

  • 29.
    Carlsson, Per-Olof
    et al.
    Ramböll Sverige AB, Gävle; ACC Glasrådgivare, Stockholm.
    Wintzell, Helene
    KTH Royal Institute of Technology, Stockholm, Sweden; Helene Wintzell AB.
    Glaumann, Mauritz
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Eriksson, Ola
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Malmqvist, Tove
    Miljöstrategisk analys – fms, KTH, Stockholm.
    Ohring, Ilari
    Miljöstrategisk analys – fms, KTH, Stockholm.
    Svenfelt, Åsa
    Miljöstrategisk analys – fms, KTH, Stockholm.
    Finnveden, Göran
    Miljöstrategisk analys – fms, KTH, Stockholm.
    Erlandsson, Malin
    IVL Svenska Miljöinstitutet, Stockholm.
    Lindholm, Torbjörn
    Installationsteknik, Chalmers, Göteborg.
    Andersson, Johnny
    Ramböll Sverige AB, Gävle.
    Malmström, Tor-Göran
    Installationsteknik, KTH, Stockholm.
    Testfasen i miljöklassningsprojekten: Delrapport september 20072007Report (Other academic)
    Abstract [sv]

    Denna rapport är en redovisning av resultat och underlag i testfasen imiljöklassningsprojekten.

    I januari 2005 inleddes tre forskningsprojekt med målet att föreslå ettsystem för miljöklassning av byggnader. Forskningsprojekten har engemensam projektgrupp där 27 företag ingår. Syftet med projekten är attta fram förslag till indikatorer och kriterier för klassning inom områdenaenergi, innemiljö och farliga ämnen. Projekten avslutas hösten 2007.

    Under perioden december 2006 – mars 2007 genomfördes ett test avflera alternativa förslag till indikatorer. Testet utfördes i nära samverkanmed 16 företag från projektgruppen och ytterligare 10 bostadsrättföreningaroch 6 småhusägare. Sammanlagt ingick 46 byggnader av olika typ(flerbostadshus, kontor, sjukhus, småhus etc.).

    Testet utfördes genom att företag, föreningar och småhusägare samladein nödvändiga data för klassning av ett antal preliminära indikatorer. Defick också svara på frågor om prioritering av aspekter, indikatorer ochvilka resurser som krävdes.

    Insamlingen av mätdata kompletterades sedan med intervjuer för att fåin ytterligare information och synpunkter.

    Denna rapport innehåller resultat i form av:

    • Indata från dem som testat.
    • Försök till klassning av respektive byggnad.
    • Synpunkter på genomförandet av testningen.
    • Synpunkter på klassningssystemet.

    Dessutom ingick en studie av kopplingen mellan energideklarationer ochmiljöklassning. Några av byggnaderna energideklarerades och dessa datajämfördes med vad som behövs för miljöklassning.

    Rapporten innehåller samtliga dokument från testningen och kommeratt vara ett viktigt underlag i det fortsatta arbetet. Under hösten 2007kommer ett förslag till klassningssystem att presenteras.

  • 30.
    Castro Herce, Anabel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Analysis of the condensation problem on the inner surface of Fullriggaren's large vertical window2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This Thesis is focused on the study of the problem of condensation on the inner surface of Fullrigaren building’s large single pane window. This has serious consequences as water on the floor, corrosion or mould growth.

    As the climate in Nordic countries is cold for several months a year, windows are a crucial part in building envelopes. Condensation on a window may be suitably discussed only with respect to the climate considered as cold, moderate and warm climates pose different requirements on the windows, and this is why a characterization of Gävle by its climate is necessary.

    This Thesis will include the energy analysis of the staircase considered which is required to understand the source of the actual problem. Both heat and moisture transfer will be studied. In this purpose, an IDA model will be built to simulate the conditions throughout the year and hand-made calculations will be done for the average and most critical situations. The results show that condensation will already occur for the monthlyaverage conditions having as an additional problem that if temperature drops below zero it will freeze.

    Results will also be compared to an initial installation of a 2 pane window reaching as a conclusion that its original installation would had avoided the problems for most of the time.

    The Thesis will end with several proposals posed to solve the problem by either increasing the temperature or reducing the moisture content of the ambient air, and the selection of the best one. The final aim of the Thesis is to achieve an energy efficient window which should provide good lighting during the day and good thermal comfort both during day and night at minimum demand of paid energy. And for this, the selection of the electrically heated window is proposed.

  • 31.
    Catalan Solsona, Juan Antonio
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    The flow impact on a radiator system: A case study in district heating system2016Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
  • 32.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Mapping tracer gas concentrations using a modified Low Third Derivative method: numerical study2019In: The International Journal of Ventilation, ISSN 1473-3315, E-ISSN 2044-4044, Vol. 18, no 2, p. 136-151Article in journal (Refereed)
    Abstract [en]

    In indoor applications, computed tomography is the process of transforming a network of intersecting attenuation measurements into a spatially resolved two-dimensional concentration map. In this study the Low Third Derivative method (LTD) was numerically evaluated and optimized for different conditions. A modified version of the LTD algorithm (LTDm) was proposed and evaluated against the original version. Eight test maps were reconstructed under different conditions, such as weight ratio, pixel resolution, beam density and measurement noise. Performance of both LTD algorithms was found to be intimately related to the number of peaks and complexity in the test map and the steepness of the peaks. The LTDm algorithm improved the quality, especially for concentration maps including steep gradients and regions with very low concentrations. The LTDm method heavily lessened aliasing distortions and efficiently minimized the effects of noise.

  • 33.
    Cehlin, Mathias
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Karimipanah, Taghi
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Larsson, Ulf
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Ameen, Arman
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Comparing thermal comfort and air quality performance of two active chilled beam systems in an open-plan office2019In: Journal of Building Engineering, E-ISSN 2352-7102, Vol. 22, p. 56-65Article in journal (Refereed)
    Abstract [en]

    The traditional air distribution and supply devices in ventilated rooms are not always able to effectively remove excess heat from the space. Therefore, chilled beams, especially the active systems, are used to achieve the desired cooling demand. The focus of this paper was the potential benefit of a newly designed active chilled beam (ACB) system, to improve heat removal effectiveness local thermal condition and indoor air quality in the occupants’ breathing zone. The system based on 1-way flow design (1W-ACB) was installed in an open-plan office and its performance was studied by analysing the temperatures, velocities and tracer gas concentrations in predetermined risky zones. The system was compared against a traditional 4-way flow design (4W-ACB).

    The obtained results showed that heat removal effectiveness was slightly higher for the 1W-ACB system compared to the 4W-ACB system. The local thermal condition was very good close to the workstations when using 1W-ACB. The benefits of the new system were also shown in the occupied zone by analysing the mean age of air and air-change effectiveness (ACE) in the breathing level at the workstation locations. The 1W-ACB system provided air with lower mean age (fresher air), and therefore higher ACE, near the breathing zone at the workstations compared to the 4W-ACB. On the other hand, the 4W-ACB system had the advantage of providing high thermal and mean age of air uniformity throughout the room.

  • 34.
    Cehlin, Mathias
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik.
    Karlsson, Fredrik
    Linköping Universitet.
    Komfort- och inomhusmiljökonsekvenser av strukturerad energieffektivisering av vårdlokaler2009Report (Other academic)
  • 35.
    Cehlin, Mathias
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Larsson, Ulf
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Chen, Huijuan
    RISE Research Institutes of Sweden, Division of Built Environment - Energy and circular economy, Borås, Sweden.
    Numerical investigation of Air Change Effectiveness in an Office Room with Impinging Jet Ventilation2018In: Proceedings of the 4th international Conference on Building Energy & Environment / [ed] K. Inthavong*, C.P Cheung, G. Yeoh, J.Y. Tu, Melbourne: Conference On Building Energy & Environment - COBEE2018, Melbourne Australia , 2018, p. 641-646Conference paper (Refereed)
    Abstract [en]

    Providing occupant comfort and health with minimum use of energy is the ultimate purpose of heating, ventilating and air conditioning systems. This paper presents the air-change effectiveness (ACE) within a typical office room using impinging jet ventilation (IJV ) in combination with chilled ceiling (CC) under different heat loads ranging from 6.5 - 51 W per square meter floor area. In this study, a validated CFD model based on the v2f turbulence model is used for the prediction of air flow pattern and ACE. The interaction effect of chilled ceiling and heat sources results in a complex flow with air circulation. The thermal plumes and air circulation in the room result in a variation of ACE within the room but also close to the occupant. For all studied cases, ACE is above 1.2 close to the occupants, indicating that IJV is more energy efficient than mixing ventilation.

  • 36.
    Cehlin, Mathias
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering.
    Numerical Modeling of a Complex Diffuser in a Room with Displacement Ventilation2010In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 45, no 10, p. 2240-2252Article in journal (Refereed)
    Abstract [en]

    A micro/macro-level approach (MMLA) has been proposed which makes it possible for HVAC engineers to easily study the effect of diffuser characteristics and diffuser placement on thermal comfort and indoor air quality. In this article the MMLA has been used to predict the flow and thermal behavior of the air in the near-zone of a complex low-velocity diffuser. A series of experiment has been carried out to validate the numerical predictions in order to ensure that simulations can be used with confidence to predict indoor airflow. The predictions have been performed by means of steady Reynolds Stress Model (RSM) and the results have good agreement both qualitatively and quantitatively with measurements. However, measurements indicated that the diffusion of the velocity and temperature was to some extent under-predicted by the RSM, which might be related to high instability of the airflow close to the diffuser. This effect might be captured by employing unsteady RSM. The present study also shows the importance of detailed inlet supply modeling in the accuracy of indoor air prediction.

  • 37.
    Cehlin, Mathias
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik.
    Moshfegh, Bahram
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik.
    Visualization of Isothermal Low-Reynolds Circular Air Jet Using Computed Tomography.2005In: Proceedings of 6 th World Conference on Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics, 2005Conference paper (Refereed)
    Abstract [en]

    The intention of this paper was to demonstrate the principle and usefulness of computed tomography for concentration field measurements. Radial extinction coefficient profiles have been reconstructed using the LTD approach in the transition region of an isothermal jet of air at Reynolds number of 2 600. Reconstructed profiles were compared against velocity profiles at axial distances ranging from 2 to 20 nozzle diameters downstream. Results indicate that the width parameter of the reconstructed scalar distribution is around 23 % larger than the velocity distribution for distances between 10 and 20 nozzle diameters downstream. This finding is in good agreement with the results of other investigators. This technique has evidently yielded an accurate description of the scalar field of the round isothermal free jet.

    The quality of the reconstructions is very promising considering the relatively few measurement data, projection angles and low pixel resolution used in this study.

    Ccomputed tomography is superior for monitoring chemical concentrations over larger areas (whole room) when PMS and PLIF are unfeasible.

  • 38.
    Cehlin, Mathias
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik.
    Moshfegh, Bahram
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik.
    Karlsson, Fredrik
    Larsson, Ulf
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik.
    Analysis on Thermal Comfort for a Hospital Building by Multi-zone Modeling: Summer Condition2008In: Proceedings of World Renewable Energy Congress X, 2008Conference paper (Refereed)
  • 39.
    Cehlin, Mathias
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik.
    Moshfegh, Bahram
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik.
    Stymne, Hans
    Mapping of Indoor Climate Parameters in Volvo, Eskilstuna2000Report (Other academic)
  • 40.
    Cehlin, Mathias
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik.
    Sandberg, Mats
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för inomhusmiljö.
    Computed Tomography for Indoor Applications2006In: The International Journal of Ventilation, ISSN 1473-3315, E-ISSN 2044-4044, Vol. 4, no 4, p. 349-364Article in journal (Other academic)
    Abstract [en]

    This paper deals with tomographic techniques for two-dimensional spatially resolved concentration measurements indoors. This represents a significant advance over the traditional point measuring method for mapping tracer gas and pollutants. Methods for recording of data are stressed as well as different types of tomographic reconstruction algorithms such as the Smooth Basis Function Minimization (SBFM) and the modified Low Third Derivative (LTDm) methods. Among the reconstruction algorithms available today, SBFM and LTDm are among the most promising. These algorithms show potential for reconstruction of gas concentration in rooms, since they are regularized to converge towards smooth concentration distributions. Using the LTD method and ‘snapshot’ configuration enables the examination and real-time monitoring of transient flows.

  • 41.
    Cehlin, Mathias
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik.
    Sandberg, Mats
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för inomhusmiljö.
    Time evolution of gravity currents discharged from low velocity diffusers2007In: Roomvent 2007, 2007, p. 61-70Conference paper (Refereed)
  • 42.
    Dahlberg, Håkan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    LCC på ventilationssystemet på en skola: en undersökning huruvida VAV eller CAV är mest ekonomiskt i längden2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When designing today, the building designer is often faced with the choice of planning for either ventilation with constant flow or variable flow. Furthermore the flows can be varied manually or automatically. The building designer has to take into account the cost of the investment, but also potential energy- and cost savings over time. Many times it is difficult to know how energy is affected by the various systems making it difficult to choose the most optimal system.This work investigates the LCC present value at a school in Uppsala with three different systems, either CAV with timer, manually controlled VAV or automatic VAV with is controlled by temperature and CO2. The main reason is that schools consist of a variety of classrooms and facilities that are not always used during school time, the risk is that schools can be over ventilated with a traditional CAV. Johansson (2005) showed that VAV can be financially feasible in schools why the purpose of this thesis is to see how it is in this current case, and which solution is the most economical.The school is simulated with software VIP Energy 2.0.8 where the three different operating conditions are investigated and how energy changes with varied ventilation rate. The temperatures in the classrooms are also simulated and observed. The costs of the various installations are presented where it appears more advanced systems are significantly more expensive. The cheapest solution costs 450 000 SEK while the most expensive costs 680 000 SEK. Furthermore the thesis also discuss the cost of capital, energy price and energy price changes, and where two different discount rates, 5% and 10%, is used. A Sweden Price on energy is presented, but also a Europe-adapted option where electricity price is predictable more expensive. Real energy prices are expected to increase by 3% per year.The results show that the energy savings due to the more advanced variable systems is marginalized because of the expensive investment costs. In some cases it shows that a manual control of ventilation VAV may be economic considerations.A problem arises, however, with reduced ventilation during the summer months as the temperatures exceeds the maximum levels Socialstyrelsen made.

  • 43.
    Djuric Ilic, Danica
    et al.
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Ödlund, Louise
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Åberg, Magnus
    Department of Engineering Sciences, Uppsala University, Uppsala, Sweden.
    No zero burden assumption in a circular economy2018In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 182, p. 352-362Article in journal (Refereed)
    Abstract [en]

    A majority of previous studies on environmental problems caused by waste generation have focused on waste disposal issues without fully highlighting the primary reasons behind the problems. As a consequence, efforts to reduce these problems are usually directed towards the stakeholders that provide waste treatment and disposal instead of the stakeholders that contribute to waste generation. In order to detect connections between different problems of sustainability and to suggest measures which may contribute to their solutions, this study provides a simplified overview of the mechanisms behind waste generation and management. The results from the study show that the only way to eliminate problems of sustainability is to apply an upstream approach by dealing with the primary problems which occur in the early stages of the system (e.g. overconsumption of products, as well as use of finite resources, toxic materials, and non-recyclable materials). By dealing with these problems, the emergence of secondary problems would be prevented. Thereby, stakeholders who have the highest possibility to contribute to the sustainable development of the waste generation and management are the stakeholders from the origin of the product's life cycles, such as product developers, manufacturing companies, product users and policy makers. Different trade-off situations such as contradictions between economics, recyclability, energy efficiency, make it even harder to deal with issues of sustainability related to the system and to detect the stakeholders who may contribute to the development. One of the main conclusions from this study is that when transforming society towards a circular economy, the traditional view of separate systems for production and waste management must be changed. In order to refer to all problems of sustainability and also cover the top steps of the waste hierarchy, life cycle assessment of waste management should include manufacture and use of products ending up as waste. Waste entering the waste management system with “zero burden” by releasing the previous actors of the waste life cycle from any responsibility related to the environment (i.e. by shifting the total environmental burden into the waste management system), does not capture the problems with waste generation.

  • 44.
    Eissa, M. M.
    et al.
    Electrical Power and Machines Engineering, Helwan University, Egypt.
    Virk, Gurvinder S.
    Electrical Power and Machines Engineering, South Westphalia University, Germany.
    AbdelGhany, A. M.
    Electrical Power and Machines Engineering, Helwan University, Egypt.
    Ghith, E. S.
    Optimum Induction Motor Speed Control Technique Using Particle Swarm Optimization2013In: International Journal of Energy Engineering, ISSN 2163-1891, E-ISSN 2163-1905, Vol. 3, no 2, p. 65-73Article in journal (Refereed)
    Abstract [en]

    Industrial processes are subjected to variation in parameters and parameter perturbations, which when significant makes the system unstable. In order to overcome this problem of parameter variation the PI controllers are widely used in industrial plants because it is simple and robust. However there is a problem in tuning PI parameters. So the control engineers are on look for automatic tuning procedures. In recent years, many intelligence algorithms are proposed to tuning the PI parameters. Tuning PI parameters using different optimal algorithms such as the simulated annealing, genetic algorithm, and particle swarm optimization algorithm. In this paper a scheduling PI tuning parameters using particle swarm optimization strategy for an induction motor speed control is proposed. The results of our work have showed a very low transient response and a non-oscillating steady state response with excellent stabilization. The simulation results presented in this paper show the effectiveness of the proposed method, with satisfied response for PSO-PI controller.

  • 45. Ekvall, Tomas
    et al.
    Malmheden, Sara
    Hållbar avfallshantering: populärvetenskaplig sammanfattning av Naturvårdsverkets forskningsprogram2012Report (Other academic)
  • 46. Ekvall, Tomas
    et al.
    Malmheden, Sara
    Towards Sustainable Waste Management - Popular Summary Report from a Swedish EPA Research Programme2014Report (Other academic)
    Abstract [en]

    The purpose of the research program Towards Sustainable Waste Management has been to assemble, develop and evaluate ideas for policy instruments for a more sustainable waste management. The waste management should contribute to reducing the environmental impact of the society, for example through reduced waste quantities and increased recycling. It should be cost-efficient and also be accepted among the public as well as other important stakeholders. Our aim was also to develop tools and methods to evaluate such instruments. For example we have developed a package of computer models to analyse the quantities of waste that can arise in the future (EMEC), how these different quantities might be treated (NatWaste), and how this can affect the environment (SWEA). The models also provide information about the cost of waste management and how the Swedish economy in general can be affected by the policy instruments. This package of models, together with our other models and methods, give us a unique capability for the assessment of new policy instruments and the analysis of complex questions on waste quantities and waste treatment. Our assessments and conclusions have a broad scientific basis. We combined the three models above with other calculations and with qualitative analysis and discussions, based on research in ethnology, psychology, economics, etc. This means that we are also able to analyze issues of acceptance and discuss how information should be designed to be effective. People often like to contribute to a good environment, through source separation, etc. However, each individual has a clear limit regarding how much effort to spend. A positive attitude towards source separation does not reach far, when the sorting of a waste fraction is considered difficult. Hence, it must be easy to do the right thing. We found that people who are not satisfied with the waste-management system are uncertain over it rather than unhappy with it. Clear information can be of great benefit, if adapted to the situation and audience, and especially when combined with other policy instruments. Besides information, we assessed fifteen other policy instruments that aim for waste prevention and increased recycling of materials:

    • Raw materials tax
    • Tax on hazardous substances
    • Recycling certificates
    • Prohibition of distribution of advertising to households that have not expressly agreed to this
    • Reduced value added tax (VAT) on services
    • Negative labeling of products with hazardous substances
    • Requirements for companies to work on waste minimization
    • Improved surveillance by authorities
    • Weight-based waste-collection fee
    • Environmentally differentiated waste-collection fee
    • Consumer-friendly waste collection systems
    • Climate Tax on incineration of waste with fossil origin
    • Weight-based tax on incineration of waste
    • Green electricity certificates for waste incineration
    • Obligation to recycle recyclable materials

    Of these, the obligation to recycle recyclables seems to provide the greatest environmental benefit. A weight-based waste fee also results in increased source separation and recycling. Raw material taxes and recycling certificates aim at stimulating or requiring a demand for recycled materials. The introduction of such instruments in a single country like Sweden has a small effect on the total recycling of the materials, partly because the supply of recycled material is insensitive to changes in the market. Reducing VAT on services helps to shift consumption away from goods to services. This reduces the quantity of waste per consumed Euro. The quantity of paper waste in the households is reduced if the distribution of advertising is prohibited to households that have not expressly agreed to this. The waste quantity can also be reduced through demanding waste-minimization plans or similar in companies and through improved surveillance of the companies by authorities. We expect each of these instruments to affect the waste quantity with a few percent or less, but together they can still have a significant effect. Some instruments are complementary and therefore good to combine. It is, for example, a good idea to combine the weight-based waste-collection fee with consumer-friendly collection and information, because this reduces the risk that households dispose of their waste illegally. Information can be a powerful tool if it is combined with other instruments, but isolated it is difficult to get it effective. In Towards Sustainable Waste Management we evaluated one or two versions of each instrument. Our studies in addition gave ideas for new versions of some of the investigated instruments and also ideas for completely new instruments. A substantial tax on the use of materials could, for example, lead to increased material efficiency in industry. Support to repairing services could extend the life of certain products and thus reduce the waste quantity. Allowing temporary landfill or storage of plastic waste that cannot be recycled could reduce greenhouse gas emissions. Well established tools like deposit systems and the landfill tax could be expanded to include more products and waste fractions. Further research or investigations are needed both on these new ideas about the instruments we have studied, to determine whether – and if so, how – they are inserted into practice. Among the instruments in place today, and also among the possible policy instruments that we have studied, there are a few that greatly affect the treatment of waste. Examples include landfill bans, the extended producer responsibility, and the obligation to recycle recyclables. However, it is more difficult to find instruments that drastically can reduce the waste quantity. This quantity seems to be decided mainly by the economic and technological development in the society, and by consumption patterns and the lifestyle of the citizens. To find policy instruments that can greatly reduce the quantity of waste we need further innovation in this area. The results from the research program have been published in more reports, scientific articles, etc., many of them in English. Visit our website www.sustainablewaste.info for a full list of publications.

  • 47.
    Eliasson, Dennis
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Kyla med värme: En jämförelsestudie med huvudfokus på fjärrvärmedriven kyla2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this thesis is to evaluate and compare a number of selected chilling techniques, with a main focus on heat driven cooling. Mainly for an existing building, but also a more general comparison that can be used as a basis for other projects. This thesis has been carried out in cooperationwith ÅF in Borlänge.The building that has been investigated is located in Borlänge. All calculations and assumptions regarding the district heating network are based on Borlänge Energi’s district heating network. The main purpose has been to compare the different cooling techniques from an economical point of view, but also a slight comparison from an environmental point of view. In addition, the purpose has been to investigate how a district heating supplier can deliver cooling to its customers without having to dig down newdistrict cooling pipes.

    The cooling techniques compared in this thesis are absorption chillers, adsorption chillers, sorptive cooling and conventional electrical compression chillers. In order to compare the different techniques, the total life cycle cost has been calculated. Investment costs and data have been obtained from skillful salesmen representing variouscompanies. Operating costs have been calculated using data and energy prices from Borlänge Energi. Costs for installation, shipping and lifting are not included in this thesis.

    The most cost-effective solution for the existing building is to install an absorption chiller, closely followed by complementing the existing cooling system with free cooling. The absorption chillers has very low operating costs during the summer, when the price of the district heating is at its lowest. The most expensive technique are adsorption cooling, due to its expensive investment cost and its low efficiency.

    For the general comparison, it was found that the most cost-effective solution is absorption chiller as well, closely followed by the conventional compressor chiller. The absorption chillers has much lower operating costs than its competitors, but the compressor chiller has a lower investment cost and a much better efficiency.

    If Borlänge Energi were to sell district heat-produced cooling during the summerusing an adsorption chiller, they would have a payback time of only approximately 2 years, with a cooling power of 655kW. With a cooling power of 100 kW, the payback time would be approximately 5 years.

    Conclusions can be drawn from this thesis that buildings with higher cooling demand are better suited for heat-driven cooling.

  • 48.
    Eriksson, Denise
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Energibalans för Norra stegvalsverket: En fallstudie på Sandvik AB i Sandviken2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In 2014, industrial operations in Sweden consumed nearly 40% of the total energy use. The steel and metal industry uses the second largest amount of energy in the industrial sector, only the pulp and paper industry uses more. A large part of the energy is waste heat and is often considered as waste. I many cases the waste heat can be used for district heating if it has sufficiently high temperature.

    This thesis has been taken as a case study at the steel industry Sandvik. The aim of this study is to develop an energy balance for one of the buildings at the plant. Another purpose is to investigate whether there is a possibility to reuse the heat from the cooling system. The building that has been investigated is called Norra stegvalsverket, which is a cold-pilger mill. To reach the goal with this study, a literature study has been conducted, a case study containing some measurements of flows and temperatures, as well as a variety of interviews. To generate an energy balance, it is required that the energy flow of the building is mapped. The energy that is added is electricity, steam, and internal heat. The energy that the building consumes is transmission, ventilation, cooling water, and uncontrolled ventilation. The study has been limited to one building and no technical solutions have been investigated.

    The result of this work show that the temperature of the cooling water is too low to be used for district heating unless it is upgraded to a higher temperature. One possible application for the cooling water is to preheat the ventilation air. The study also shows that there is too little detailed information regarding the use of electricity in the building. The problem was discovered at the end of the project, which meant that there was no time to make further measurements. Due to this problem, the study does not give a fair picture how the energy is distributed in Norra stegvalsverket. To develop this study, a thorough investigation of the electricity usage is required to find exactly how much electricity the building uses. A study could also be carried out to find out if there are technical and economic opportunities to preheat the ventilation air with the cooling water.

  • 49.
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Energy and Waste Management2017In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 10, no 7, article id 1072Article in journal (Refereed)
    Abstract [en]

    Waste management and energy systems are often interlinked, either directly by waste-to-energy technologies, or indirectly as processes for recovery of resources-such as materials, oils, manure, or sludge-use energy in their processes or substitute conventional production of the commodities for which the recycling processes provide raw materials. A special issue in Energies on the topic of “ Energy andWaste Management” attained a lot of attention from the scientific community. In particular, papers contributing to improved understanding of the combined management of waste and energy were invited. In all, 9 papers were published out of 24 unique submissions. The papers cover technical topics such as leaching of heavy metals, pyrolysis, and production of synthetic natural gas in addition to different systems assessments of horse manure, incineration, and complex future scenarios at a national level. All papers except one focused on energy recovery from waste. That particular paper focused on waste management of infrastructure in an energy system (wind turbines). Published papers illustrate research in the field of energy and waste management on both a current detailed process level as well as on a future system level. Knowledge gained on both types is necessary to be able to make progress towards a circular economy.

  • 50.
    Eriksson, Ola
    Centrum för miljöstrategisk forskning, Kungliga Tekniska Högskolan, Stockholm; Institutionen för infrastruktur och samhällsbyggnad, Kungliga Tekniska Högskolan, Stockholm.
    Fjärrvärme i ett ekologiskt hållbarhetsperspektiv2004Report (Other academic)
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