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One way to tackle the climate change society is facing today is through the change to renewable energy sources, such as wind power. Today, a trend when it comes to technology is that products are evolving into becoming more cyber-physical systems (CPS) by integrating functions realized with mechanics, control and communication. One challenge for CPS is to find cost-effective and reliable sensor solutions. The purpose of this project is to lay the foundations for an intelligent CPS with the help of sensors and condition monitoring methods that, with further development, can reduce the downtime of a wind turbine. Thus, the reliability of the wind turbine and the profitability of its investors increase. The aim of the work is to develop an overall concept for a sensor package with analysis methods that enable real-time diagnosis in the gearbox of a wind turbine. This sensor package should be able to monitor the most common problems that arise in the gearbox and it should also be able to be used as a basis for a possible development of a CPS in the future. The work is based on an information search that enables the creation of a list of requirements. This then forms the basis for concept generation through the use of a function/means tree and concept evaluation through the use of elimination matrix, weight determination matrix and weighted criteria matrix. The work concludes that there are four main types of failures that occur in the gearbox and that should be monitored. These are scuffing, micropitting, propagation of cracks and bearing failure. The final concept uses vibration analysis for monitoring of micropitting, crack propagation and bearing failure, oil analysis for monitoring of scuffing and micropitting and temperature measurement for monitoring of scuffing and bearing failure. For vibration analysis, piezoelectric sensors are used, for oil analysis electromagnetic sensors and for temperature measurement resistance thermometers are used. The work finds that it is appropriate in this day and age to use well-established methods for condition monitoring in the gearbox of wind turbines. Ett sätt att tackla de klimatförändringar samhället står inför idag är genom omställningen till förnybara energikällor, såsom vindkraft. Idag är en trend när det kommer till teknik att produkter utvecklas till att allt mer bli cyberfysiska system (CPS) genom att de integrerar funktioner som realiseras med mekanik, reglering och kommunikation. En utmaning för CPS är att hitta kostnadseffektiva och tillförlitliga sensorlösningar. Syftet med detta projekt är att lägga grunden till ett intelligent CPS med hjälp av sensorer och tillståndsövervakningsmetoder som med vidare utveckling ska kunna minska stilleståndstiden hos ett vindkraftverk. Således ökar tillförlitligheten hos vindkraftverket samt räntabiliteten för investerarna av dessa. Arbetets mål är att utveckla ett övergripande koncept för ett sensorpaket med analysmetoder som möjliggör realtidsdiagnos i växellådan hos ett vindkraftverk. Detta sensorpaket ska kunna övervaka de vanligaste problemen som uppstår i växellådan och ska kunna användas som grund för eventuell utveckling av ett CPS i framtiden. Arbetet grundas i en informationssökning som möjliggör skapandet av en kravspecifikation. Denna ligger sedan till grund för konceptgenerering genom användandet av funktions/medelträd samt konceptutvärdering genom användandet av elimineringsmatris, viktbestämningsmatris samt kriterieviktsmetoden. I arbetet framkommer att det finns fyra huvudsakliga skador som uppkommer i växellådan och som bör övervakas. Dessa är scuffing, mikropitting, sprickpropagering och lagerhaveri. Det slutgiltiga konceptet använder vibrationsanalys för övervakning av mikropitting, sprickpropagering och lagerhaveri, oljeanalys för övervakning av scuffing och mikropitting samt temperaturmätning för övervakning av scuffing och lagerhaveri. Vid vibrationsanalys används piezoelektriska sensorer, vid oljeanalys elektromagnetiska sensorer och för temperaturmätning resistanstermometrar. Arbetet konstaterar att det i dagsläget är lämpligt att använda väletablerade metoder för tillståndsövervakning i växellådan hos vindkraftverk.

Land, energy and water are the foundational resources of a country, and have a number of complex interactions with a changing climate. Their exploitation can have significant impacts on climate change, which in turn can affect the future availability of these resources. Thus it is important to properly manage these resources, to ensure that they can continue to provide long into the future. This thesis aims to assess the climate, land-use, energy and water systems (CLEWs) nexus in Bolivia, to determine critical points of interactions, and to produce recommendations for policy actions. This includes both mitigation and adaptation actions. The results show that Bolivia’s projected demand increases are certainly manageable, and with the investments as outlined, they can easily be satisfied, while reducing emissions and increasing climate resilience. An important result is that municipal and thermal water demand don’t appear to be limiting constraints, and so water management efforts should focus on agricultural and hydropower use. Recommended future work is to increase the scope and detail of the water and land model, so that all of the planned hydropower projects are included, and so that agriculture and irrigation demands and impacts can be more accurately predicted.

Jernhusen AB är ett fastighetsbolag inom transportbranschen och är framförallt inriktade mot järnvägen. Jernhusen har ett uttalat mål att bidra till ett hållbart samhälle. Som ett steg i detta vill Jernhusen undersöka möjligheterna med att investera i lokalproducerad förnybar energi på deras tågunderhållsdepåer.Denna rapport utreder förutsättningarna och möjligheterna med detta. Det finns idag flera olika förnybara energikällor som kan användas lokalt på depåerna. De bäst lämpade teknikerna för Jernhusens tågunderhållsdepåer är att använda solenergi och geoenergi. Solenergin kan användas för att producera elkraft med solceller och värme med solfångare. Det finns flera olika typer av solceller med den mest kommersiellt använda typen är polykristallina kiselsolceller. Underhållsdepåerna har stora effektbehov, både för el och för värme. Effektbehovet är som störst under vintermånaderna när tågen behöver avisas. Depåerna har stora öppna tak och bangårdar som lämpar sig till att använda både solceller, solfångare och geoenergi. De flesta depåerna är gamla och fastigheterna innehåller markföroreningar, vilka behöver beaktas om ett geoenergisystem ska installeras på fastigheten. Det finns goda förutsättningar för Jernhusen att installera olika system som utnyttjar förnybara energikällor. Om ett solcellssystem skulle installeras på Hagalund enligt Tabell 6-1 är återbetalningstiden för investeringen 15 år. Detta får anses som en god investering då ett solcellssystem kan ha en livslängd på 40 år. Hade en geoenergisystem installerats på Raus enligt Tabell 6-3 blir återbetalningstiden 17 år. Ett solfångarsystem har låg lönsamhet oavsett vilket depå det installeras på. Dock blir både geoenergi och solfångare betydligt mer lönsamma om byggnaden är uppvärmd av direktverkande el eller vid nybyggnationer. Jernhusen AB is a real estate company within the transportation industry and their business is focused towards the railway. Jernhusen has a stated goal that the company should contribute to a sustainable society. As a step in this goal the company explores the possibilities of investing in locally produced renewable energy systems at their maintenance depots. This report investigates the potential in that kind of investment. There are currently several different renewable energy sources that can be used for locally producing renewable energy at the depots. The most appropriate techniques for Jernhusen to use are solar energy and geothermal energy. Solar energy can be used to produce electric power with solar cells and to produce heat with solar panels. There are several different types of solar cells but the most commonly used are polycrystalline silicon based solar cells.The maintenance depots have large power requirements for both electricity and heat. The power demand is greatest during the winter months when the train needs de-icing. The maintenance depots have large open roofs and rail yards suitable for solar cells, solar panels and geothermal systems. Most of the depots are old constructions and the properties contains a lot of soil pollution that need to be considered if a geothermal energy solution is up for investigation. There are good prospects for Jernhusen to install various systems using renewable energy sources. If a solar cell system were installed at Hagalund according to Table 6-1 the payback period for the investment is 15.1 years. This must be seen as a good investment when the solar cells have a lifespan of 40 years. If a geothermal system were installed at Raus according to Table 6-3 the payback period is 17.2 years. A solar panel system has a low profitability regardless of which depot the system is installed at. However, both the geothermal system and the solar panel system are far more profitable if the building is heated by electricity.

Sweden has a large multifamily housing stock that was built between 1960 and 1975. An important current issue is how this stock can be renovated in a sustainable way. The article analyses a strategy used by a suburban municipal housing company that had clear social ambitions and offered the tenants three options of renovation: Mini, Midi and Maxi. Most tenants chose the Mini alternative which meant that they could afford to stay and that there was no increase in costs for the social authorities. An investment analysis showed that the Mini alternative had a positive net present value, but that the Midi and Maxi alternatives were more profitable. Even though there was no clear environmental focus in the renovation, energy use was reduced by 8%. As a conclusion, the study shows that a sustainable renovation is possible but that there are a number of conflicts between the different dimensions of sustainability.

The project under discussion is the FPSO Ichthys. The FPSO is a ship comprising the offshore production facility for an oil&gas field, financed by INPEX/Total. An oil platform extracts the product received via the flexible risers and separates it into gas and condensate. The condensate is transferred to the FPSO, which processes it, and separates it between natural gas and oil. The oil is stored in the FPSO and then exported via a tanker. The gas is transferred via a pipeline. An FPSO is a complex installation in many respects. It is a condensate treatment factory, installed on a 450-metre-long ship. It should have the capacity to store one week’s condensate production. The FPSO is self-sufficient in terms of energy production (electricity, heating and cooling). Owing to the proximity of the hazardous production area to the living quarters, strict safety regulations are applied. For instance, all equipment has to be designed with redundancy (2x50% or 3x33% for critical equipment); the heating and cooling systems are managed with the help of emergency logic diagrams. These enable vital functions to be maintained even in cases of extreme failure. Despite its complexity, the FPSO has to be constructed within a short period of time. However, safety issues are important, and maintenance of defective equipment is expensive since the ship will be located 300km away from the coast. This is the reason why the constructor contracted Actemium, a part of VINCI Energies. Actemium commissions the FPSO. The commissioning mission has to prove that the systems function in accordance with the designs. Commissioning occurs right after the pre-commissioning (de-energized verifications). Commissioning is divided into three main activities: functional tests (which prove that individual pieces of equipment work in accordance with the designs); operational tests (which prove that all subsystems work in accordance with the designs of different modes); and piping and vessels pressurization (which prove that there is no leak). This master thesis describes the requirements of such projects and focuses on the operational tests. A description of the installation is detailed. Secondly, the subcontractor for the commissioning of the project, Actemium, and the method used for the commissioning are presented thereafter. Finally, the operational test procedures of the cooling and heating systems are examined in detail.

Gas switching reforming (GSR) is a promising technology for natural gas reforming with inherent CO2 capture. Like conventional steam methane reforming (SMR), GSR can be integrated with water-gas sh ...

Waste heat can be recovered and used in different processes to increase energy efficiency and reduce CO2 emissions. It has become an attractive area of research for scientists and several techniques are being investigated and practiced to recover, store and use waste heat. Thermal Energy Storage is one of the modern techniques that is used to store and use waste heat. Energy can be stored in both sensible and latent forms of heat. Latent heat storage is the most efficient way of storing thermal energy as it provides higher storage density and lower temperature differential between storing and releasing heat. The materials that are used for latent energy storage are termed as Phase Change Materials (PCMs). This thesis work investigates the feasibility of a latent heat storage and heat exchanger performance based on phase change material to recover heat at elevated temperatures. The heat transfer study is done by using state of the art commercial CFD tool. Different model geometries of the Thermal Storage equipped with Shell and tube heat exchanger were built with different pipe configurations. The 1st type of model is a set of three 2D models built in COMSOL Multiphysics. These models constitute a cross section of a small portion of heat exchanger having four 10 mm outer diameter pipes immersed in PCM. Fins were mounted on the pipes to enhance the area for heat transfer and hence the heat transfer rate in modified models. Simulations were carried out for melting and solidification of PCM with these 2D models. After analyzing the results, a 3D model of the small block was created to get more realistic results and analyze the effect of pipe diameter on melting and solidification of PCM. The results of 2D models show the effect of fins on heat transfer rates. The model with eight fins on each pipe shows the best results as compared to other two models. The melting and solidification rates are nearly half for eight fin model as compared to the model without fins. The four fin model shows moderate results but better than the model without fins. The comparison of the results for different diameter pipes in 3D model shows that heat transfer rate increases for increasing diameters of the pipe with same flow rate in the case of melting.

Sustainability is a normative concept, building on ideas such as justice, equity and responsibility, and based on human culture and society. Computers, internet, and the technologies that are central in our network society embed also normative values and are part of a cultural context. But the work looking at computer technologies and sustainability has been mostly oriented towards either calculating the impact of technology or using technology as a tool for solving practical problems. ICT is seen as a neutral system to be used or study, while the more normative aspects are mostly overlooked. This paper explores some of the problems arising from these overlooked normative values, such as focusing only on quantifiable problems while forgetting other aspects that may be as important but not easy to put in numbers, or trusting too much in numbers while hiding assumption and model choices. This paper suggests that more critical reflection on these questions is needed in the research area, as well as developing more connections with existing research on these topics in more traditional disciplines.

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