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1	Price policy estimation for Demand Response of heat-pump-based loads / Prissättningspolicy för uppskattning av eferfrågeflexibilitet med värmepumsbaserade laster Gil Simancas, Carlos Eduardo January 2023 (has links) The electricity grids have become a key player in the society. An increased usage of electricity is both a result from the more electrified society, but also as a main solver in reaching the climate goals by reducing emissions. This thesis work explores some of the new features for the electricity grid from integration of electrification from renewable energy resources (RES) and from strategies for energy optimization related to the loads and specifically from thermal heat pumps. These strategies lie in the field of demand response, which takes advantage of the flexibility of loads in terms of willingness to switch or decrease their consumption at a particular moment of the day. This research proposes a three-step framework to harness the flexibility of Thermo-Statically controlled loads (TCLs) based on a simulated grey-box building model that uses historical outside temperature and prices data and learns the thermal parameters such as Thermal Resistance, Thermal Capacitance, but also price responsiveness (pth ) through a Differential Evolution (DE) based optimization algorithm. The price responsiveness is used to provide further insight into the flexibility of the loads and is employed in the last step to propose a price policy estimation algorithm also based on DE that minimizes the gap between supply and demand while preserving supplier and customer profitability. The proposed approach has proven to be accurate for a large number of parameters but also effective with reduced training data (prediction errors around 2.5% on the power average and standard deviation), as well as to be successful in providing a Day-Ahead Real-Time Price policy that maximizes supplier and customer utility. The price policy provides a lower total price for the customer compared with a tariff without demand response (reduction up to 53.63 %), reduces the gap between RES-based energy sources and heating demand, and respects grid technical constraints. / Elnätet har blivit en nyckelaktör i samhället. En ökad elanvändning är både ett resultat av det mer elektrifierade samhället, men också som en huvudlösare för att nå klimatmålen genom att minska utsläpp. Detta examensarbete undersöker några av de nya funktionerna för elnätet från integration av elektrifiering från förnybara energiresurser (RES) och från strategier för energioptimering relaterade till ellaster och specifikt från termiska värmepumpar. Dessa strategier ligger inom området för efterfrågerespons, som drar fördel av lasternas flexibilitet när det gäller viljan att byta eller minska sin konsumtion vid en viss tidpunkt på dagen. Den här forskningen föreslår ett ramverk i tre steg för att utnyttja flexibiliteten hos termostatiskt kontrollerade laster (TCL) baserat på en simulerad gråbox-byggnadsmodell som använder historisk utomhustemperatur och prisdata och lär sig de termiska parametrarna som termisk motstånd, termisk kapacitans , men också priskänslighet (pth) genom en Differential Evolution (DE) baserad optimeringsalgoritm. Priskänsligheten används för att ge ytterligare insikt om lasternas flexibilitet och används i det sista steget för att föreslå en prispolitisk uppskattningsalgoritm också baserad på DE som minimerar klyftan mellan utbud och efterfrågan samtidigt som leverantörs- och kundlönsamheten bevaras. Det föreslagna tillvägagångssättet har visat sig vara korrekt för ett stort antal parametrar men också effektivt med reducerad träningsdata (förutsägelsefel runt 2,5% på effektmedelvärde och standardavvikelse), samt vara framgångsrik i att tillhandahålla en Day-Ahead Real -Tidsprispolicy som maximerar leverantörs- och kundnyttan. Prispolicyn ger ett lägre totalpris för kunden jämfört med en tariff utan efterfrågerespons (reduktion upp till 53, 63 %), minskar gapet mellan RES-baserade energikällor och värmebehov samt följer nättekniska begränsningar. Differential Evolution Electricity Grids Flexibility Services Heat-pumps Heterogeneous Loads Implicit Demand Response Optimization Differentiell utveckling elnät flexibilitetstjänster heterogena belastningar implicit efterfrågesvar optimering värmepump Elektroteknik och elektronik Computer Engineering Datorteknik
2	Test Rig Adaptation for the Investigation of Bearings in Wave Energy Converters / Testriggsanpassning för undersökning av lager i Wave Energy Converters Menon, Aju Sukumaran January 2021 (has links) Wave ocean energy is a source of renewable energy which is gaining interest in the modern world. In contrast to other well-researched renewable energy sources such as wind energy, wave ocean energy is under the development phase. Governments around the world are encouraging the research of harnessing wave energy. As of now, there are different concepts to harness energy from waves. Tribological components are one of the main aspects that need attention in these wave energy converters. The moving components such as bearings can be the life-determining component of the entire device. This thesis provides conceptual solutions to adapt an existing start-stop bearing test rig to the conditions of wave energy converters. The test rig can test different bearing sused in the wave energy converters. The new design intends to provide scaled wave energy conditions. These conditions are mainly influenced by the oscillating movement of the bearings, the complex load condition and the salty environment. Since the testing of bearings in wave energy converters is in the initial stage, modular designs are implemented to test different types of bearings. / Se filen Test rig Ocean wave Oscillating motion Varying loads Wave energy converters Rolling element bearings Sliding bearing Scaling Seawater Testrigg havsvåg Oscillerande rörelse Varierande belastningar Omvandlare för vågsenergi Rullande lager Glidlager Skalning Havsvatten Mechanical Engineering Maskinteknik
3	Optimerad sandwichvägg i prefabricerad betong / Optimized sandwich wall in prefabricated concrete Alsmail, Majed, Rubaij, Baqer January 2023 (has links) As part of the work in this project, a literature review is conducted to determine the optimal thickness of the outer concrete layer in prefabricated concrete sandwich elements. These elements are used as exterior walls in buildings and consist of a load-bearing inner concrete layer, an intermediate insulation layer, and an outer concrete layer that forms the building's facade. The focus is on optimizing the sandwich wall in precast concrete by reducing the thickness of the outer skin compared to the current standard thickness of 80 mm. This could potentially reduce the weight of the elements by approximately 1.5-2 tons by reducing the thickness from 80 mm to 30 mm. This weight reduction can have a significant impact, for instance, on the crane capacity in large construction projects, allowing a crane to handle all the elements on a construction site without the need for relocation. Additionally, this optimization of the sandwich wall will result in cost savings by using less material in the elements, as well as impacting other aspects of the construction process, such as energy consumption and transportation costs. In this project, test specimens of size 400mm x 400mm have been used, and to draw comprehensive conclusions, full-scale experiments are required to account for factors such as temperature variations and shrinkage in the outer skin. In this work, compressive strength tests have also been conducted to determine the strength of the concrete used in the outer skin of the tested sandwich walls. The concrete used in the tests was a fiber-reinforced concrete from Finja, and the reinforcing mesh was a hot-dip galvanized plaster mesh. Initially, samples were cast to test the laboratory equipment and evaluate the testing methods. Subsequently, the remaining samples were cast and tested according to a predetermined schedule to ensure relevant testing conditions. Samples on the wall elements were made with both diagonal and straight anchoring and were tested under tensile load parallel to the outer layer as well as tensile load perpendicular to the outer layer. In total, 20 samples were conducted in the study, testing various combinations of anchoring systems, loads, reinforcement, and recesses. Samples 1-10 were tested with diagonal anchoring and parallel load, while samples 11-20 were tested with perpendicular anchoring and perpendicular in combination with parallel load. The samples exhibited a variation in failure types, such as grain failure in the outer layer, anchor pull-out, adhesion, and outer layer failure. The highest load values were observed in sample 2 (8.7 kN) and 6 (7.6 kN) for samples 1 to 10, and sample 12 (10.6 kN) and 15 (9 kN) for samples 11 to 20. In summary, it can be stated that the trials have yielded initially positive results regarding the practical use of a thinner outer panel for prefabricated concrete sandwich elements. sandwich elements thin concrete slabs outer concrete layer anchoring anchoring systems granular rupture in outer layer anchor pull-out adhesion outer layer failure loads reinforcement recesses sandwichelement tunna betongskivor yttre betongskiva förankring förankringssystem konbrott i yttre skivan bygel utdrag vidhäftning brott i ytterskiva belastningar armering ursparningar Miljöanalys och bygginformationsteknik
4	Load Control Aerodynamics in Offshore Wind Turbines / Aerodynamik av laststyrning i havsbaserade vindkraftverk Cantoni, Lorenzo January 2021 (has links) Due to the increase of rotor size in horizontal axis wind turbine (HAWT) during the past 25 years in order to achieve higher power output, all wind turbine components and blades in particular, have to withstand higher structural loads. This upscalingproblem could be solved by applying technologies capable of reducing aerodynamic loads the rotor has to withstand, either with passive or active control solutions. These control devices and techniques can reduce the fatigue load upon the blades up to 40% and therefore less maintenance is needed, resulting in an important money savings for the wind farm manager. This project consists in a study of load control techniques for offshore wind turbines from an aerodynamic and aeroelastic point ofview, with the aim to assess a cost effective, robust and reliable solution which could operate maintenance free in quite hostile environments. The first part of this study involves 2D and 3D aerodynamic and aeroelastic simulations to validate the computational model with experimental data and to analyze the interaction between the fluid and the structure. The second part of this study is an assessment of the unsteady aerodynamic loads produced by a wind gust over the blades and to verify how a trailing edge flap would influence the aerodynamic control parameters for the selected wind turbine blade. / På grund av ökningen av rotorstorleken hos horisontella vindturbiner (HAWT) under de senaste 25 åren, en design som har uppstod för att uppnå högre effekt, måste alla vindkraftkomponenter och blad stå emot högre strukturella belastningar. Detta uppskalningsproblem kan lösas genom att använda metoder som kan minska aerodynamiska belastningar som rotorn måste tåla, antingen med passiva eller aktiva styrlösningar. Dessa kontrollanordningar och tekniker kan minska utmattningsbelastningen på bladen med upp till 40 % och därför behövs mindre underhåll, vilket resulterar i viktiga besparingar för vindkraftsägaren. Detta projekt består av en studie av lastkontrolltekniker för havsbaserade vindkraftverk ur en aerodynamisk och aeroelastisk synvinkel, i syfte att bedöma en kostnadseffektiv, robust och pålitlig lösning som kan fungera underhållsfri i tuffa miljöer. Den första delen av denna studie involverar 2D- och 3D-aerodynamiska och aeroelastiska simuleringar för att validera beräkningsmodellen med experimentella data och för att analysera interaktionen mellan fluiden och strukturen. Den andra delen av denna studie är en bedömning av de ojämna aerodynamiska belastningarna som produceras av ett vindkast över bladen och för att verifiera hur en bakkantklaff skulle påverka de aerodynamiska styrparametrarna för det valda vindturbinbladet. Wind Turbine Offshore Blade Rotor Computational Fluid Dynamics Airfoil Aerodynamic Aeroelasticity Simulation Fluid Structure Interaction Loads Control Response Harmonics Vibration Damping Flutter Trailing Edge Flaps Wind Gust Lift Drag Unsteady Pressure Velocity Vindkraftverk offshore blad rotor beräkningsvätske-dynamik flygplatta aerodynamisk aeroelasticitet simulering vätska struktur interaktion belastningar kontroll respons övertoner vibrationer dämpning fladdring bakkant klaffar vindstöt lyft Drag ostadig tryck hastighet Energy Engineering Energiteknik

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