AbstractIn relation to new building directives and regulations there is much focus on energy efficiencyand reducing the use of electricity. There is therefore a need for ventilation systems with lowSpecific fan power (SFP) and to limit or avoid the need for mechanical cooling.At the same time questions are raised concerning whether increasingly complicatedventilation systems are the best way to achieve energy efficiency. They are more vulnerablefor poor design and maintenance which especially school buildings have suffered from.This has led to the development of several natural and hybrid ventilation concepts. One ofthese which has had success in school buildings the last 15 years in Sweden and Norway isthe so-called Swedish model. Characteristic of this solution is that sub terrain culverts areused for passive cooling and heating of the ventilation air which passes through double innerwalls and is supplied to the room high on the inner wall. The supply air falls towards the floormixing in the surrounding air and spreads along the floor as displacement flow with an outletin the ceiling. This works particularly well in classrooms where the high occupation densitycreates a cooling demand large parts of the year. These schools therefore have a very low SFPfactor and no mechanical cooling.In the following report a classroom model with the Swedish ventilation concept is studiedwith the aim of developing a method of dimensioning such air flow. CFD simulations areused to confirm expected behaviour and the resulting thermal comfort and air quality attypical winter, spring and summer scenarios. Finally a Guide for preliminary design andsizing for climatization of rooms with cooling needs using the Swedish model is presented.The most important results were that there was a good correspondence between the empiricalcalculations and CFD simulations. Adequate carbon dioxide levels and temperature can beachieved without use of primary energy for heating at for outdoor temperatures above 5 ºC.There was a substantial risk of draft unless a near zone of 2-3 m is used. However the CFDmodel was limited to a slice of the classroom and the accuracy of the results suffers somewhatfrom this.Guidelines are developed for preliminary design and sizing of supply air plumes based onempirical expressions of air flow by Eimund Skåret(2000) and can be found in the appendix.

SummaryThis Master Thesis is a conclusion on work done as part of the Resource Optimizationand recovery in the Materials industry project (Roma). This project is involved in thedevelopment of a new technology for power production from low temperature heat sourcesfor off gases from aluminum production cells. The technology is based on an transcriticalRankine cycle with CO2 as a working fluid, as the work recovery circuit. The center ofthe test facility is the expander, a prototype provided by Obrist Engineering . 81 testswere perfomed to investigate the behavoir of the expander cycle. Effect of three mainparameters were investigated:• Effect CO2 massflow rate• Effect of heat source temperature• Effect of CO2 condensation pressureFor each parameter combination, the high pressure side of the expander cycle was variedin order to find the maximum power output.This study clearly showed limitation of the turbine which cannot maintain large pressuredifference probably due to large internal leakages. As a result, turbine outlet is highlysuperheated. This superheat is lost energy for the power cycle, and is simply dumpedinto the heat sink. One possible improvement would be to include a recuperator thatrecovers superheat after the pump.The results also indicate that the fan of the air loop is too small: increasing the CO2 flowrate to limit superheat at turbine outlet leads to turbine inlet temperature reduction.Last, for large CO2 mass flow rate (3.5 kgmin) which is required for proper operation ofthe turbine, the power generated is too large for the generator installed on the loop. Itstemperature reached 120 °C for some conditions. A new solution should be seeked.Based on experimental results, a mode of the power cycle was implemented in Pro/IIand simulations were run in order to find an improved design. The main goal is to beable to run the cycle at high CO2 mass flow rate: 3.5 kgmin. It was found that the airloop fan should be able to deliver up to 1 260 m3h . The new generator or braking systemshould be able to absorb up to 297 W.

LCA of buildings has become a distinguished field of LCA, and a number of previous studies have found that low energy buildings generally have better life cycle performance than conventional buildings. However, there has been a lack of studies comparing low energy buildings against passive buildings. The present study evaluates life cycle performance of two passive and two low energy buildings that are all part of the housing cooperative Løvåshagen in Bergen. Construction of the housing cooperative was completed in 2009 and measured material and operational data was used in a comprehensive LCA of the whole life cycle from cradle to grave, for twelve midpoint impact categories. The functional unit is a lifetime of fifty years of one square meter BRA of a building block apartment. Heating for low energy apartments are provided by electric resistance heaters and heating cables in the bathroom floors, while hot water heating is provided by an electric water heater. Evacuated tube thermal collectors are located on the roofs and provide passive house room heating through hydronic radiators and hydronic floor heating. They also provide hot water heating for each apartment. When solar collector output is not sufficient, heating is supplied by electric resistance elements.The LCA results show practically no difference between the climate change performances of the house models, and this is largely the result of a particularly low passive house performance. In simulation-based LCA literature there appears to be a trend of over-estimating the operational performance of passive and low energy buildings, and Løvåshagen is no exception. The measured electricity consumption is high, both compared to estimations and to the results of other, simulation-based, studies. The high consumption appears to be a result of a particularly low outdoor temperature for the year of the measured data. It is recommended to monitor the electricity consumption over the next few years of operation, and if it is not significantly reduced there is reason to suspect faults in building construction or in the solar collector system. In the case of no direct defects there is reason to re-evaluate the effectiveness of solar collectors for the climatic conditions of Bergen.

Concrete and lightweight concrete elements are today used in various building applications to a great extent all over the world. Replacing traditional thermal insulation like e.g. expanded polystyrene (EPS), extruded polystyrene (XPS) and polyurethane (PUR) by vacuum insulation panels (VIPs) is discussed in order to increase the thermal resistance without increasing the wall thickness. Compared to traditional concrete and lightweight concrete elements, slimmer elements may still achieve U-values low enough to fulfil passive house or zero energy requirements. Thus, sandwich elements with VIPs may be an alternative to the traditional solutions. However, there may be some problems related to the use of VIPs in such concrete elements. The alkaline environment in concrete may lead to reactions with the aluminium (Al) in the multi-layered laminate used as the VIP envelope, and destroy its barrier function. To investigate the influence of the alkaline environment on the durability of VIPs in general, and the VIP envelope in particular, various VIP and VIP envelope specimen experiments have been carried out. The VIPs were subjected to different alkaline solutions at different temperatures, with and without direct contact with the liquid alkaline solutions. A worst-case scenario was investigated when any additional protection of the VIPs was disregarded. The results from the VIP experiments showed various degrees of degradation effects. Depending on the temperature and the pH-value of the alkaline environment the VIPs were exposed to, physical and thermal changes were observed on some of the test specimens, while others were more or less unaffected by the exposure. In general, the temperature proved to be the hardest strain, when the VIPs in heating cabinet showed much greater signs of degradation than the VIPs at room temperature, more or less independent on the pH-value of the alkaline solution they were exposed to. Interesting results were also obtained from the VIP envelope specimen experiment, where the VIP envelope showed signs of degradation after only a short time in alkaline solution.

SammendragI denne masteroppgaven er bygningsfysiske utfordringer knyttet til garasjekjellere i boligblokker undersøkt, med mål om å redegjøre for forskriftskrav og anbefalinger samt egen forskning. Analyser av fukt- og varmetekniske problemstillinger er gjennomført ved å benytte henholdsvis WUFI 2D og THERM. Det er også gjennomført energiberegninger ved hjelp av Simien, samt økonomiske vurderinger knyttet til energimessige problemstillinger. Gjennom analyser i WUFI er det vurdert hvor vidt en kan plassere isolasjon mellom tilfarere på et betongdekke mellom oppholdsrom og delvis oppvarmede garasjekjellere. Dette var ønsket av Skanskas tekniske underavdeling Skanska Produktdesign, og er til dels ikke anbefalt av Sintef Byggforsk. Dette ble gjennomført ved å benytte et temperaturforløp over året i garasjekjelleren med 10˚C gjennomsnittstemperatur og minstetemperatur på 5˚C. Resultatene viser at dette ikke medfører fare for muggvekst eller kondens på dekkekonstruksjonen.Varmetekniske analyser har til hensikt å analysere virkningen det har å endre plasseringen av isolasjonen fra under til over betongdekket med hensyn på kuldebroer i konstruksjonen. Resultatene viser at dette har en positiv effekt, da mindre varme ledes ut gjennom betongkonstruksjonene i dekket over kjelleren. Videre er det vurdert isolasjonsalternativer for å redusere U-verdi langs total ytre lenge av ytterkonstruksjonen vist i vedlegg 1. Simuleringene viser at det har liten hensikt å isolere sofadrageren i garasjen som holder dekket oppe på undersiden, men at det gir gode resultater å legge inn 50mm isolasjon som kuldebrobryter mellom sofadrager og hulldekkekonstruksjon.Gjennom energiberegninger i Simien er primært vurdert om Skanskas strategi om å isolere etter oppvarmingsgrad er oppnådd. Varmetapet ved 50mm utvendig isolasjon på vegger og dekke mot terreng er beregnet til 257W/m2. Ved fullt isolert, 200mm utvendig isolasjon i vegg og 250mm i dekket, og fullt oppvarmet er varmetapet beregnet til 325W/m2. Varmetapet ligger lavere, og forutsetningene er oppnådd. Det er også vurdert hvor vidt det fra et privatøkonomisk ståsted er gunstig å øke isolasjonsmengden ytterligere i en delvis oppvarmet garasje. Beregninger gjennomført ved å kombinere Simien og kostnadsdata hentet fra Holte Anbud viser at dette er lite hensiktsmessig.

Riboflavin, also known as vitamin B2 and one of the most easily absorbed nutrients,can be found in many different organisms. The most abundant source of riboflavin ismilk and dairy products; however it is also present in meat, fish and certain types ofvegetables and fruit. Riboflavin is an important part of a healthy diet in order to keep skin, eyes and nervous systems healthy. Some studies indicate that riboflavin plays an important role in cancer and cardiovascular diseases.As known, milk is extremely sensitive to light. Riboflavin is one of the factorsresponsible for the light-induced degradation of milk. In combination with light andoxygen riboflavin may act as a photosensitizer. When vitamin B2 absorbs blue-greenlight, an excited triplet state of riboflavin is generated through a process called intersystem crossing. Reactive oxygen species, such as singlet oxygen, is then formed by reaction of excited riboflavin triplet with dissolved oxygen present in milk. Light exposure of milk can lead to off-flavor and damage of vitamins by reaction of singlet oxygen with amino acids and lipids in milk. Unfortunately, most of the packaging materials today do not protect milk from light completely. The formation of singlet oxygen can also be prevented by adding quenchers that are able to deactivate riboflavin triplets.Certain amino acids and carotenoids are well known flavin quenchers.The purpose of this study was to investigate how well riboflavin triplets can bequenched by amino acids cysteine, histidine, methionine, tyrosine and tryptophan. Thequenching properties of hydrophilic carotenoid crocin were studied as well. Crocinhas been under investigation of researches at the Departement of Physics at NTNU.Lumiflavin, which is one of the riboflavin’s photodegradation products, was used instead of riboflavin. The former is more stable and has similar photochemical characteristics as the latter.The quenching of lumiflavin triplets was studied by using laser flash photolysis. Itconsists of irradiating the sample under investigation with a short-lived laser flash. The method was used to measure the kinetic decay rate of lumiflavin in aqueous buffer with and without different concentrations of a quencher. The data were fitted to two different decay models. From pseudo-first-order rate constants the quenching rate constants were determined for each amino acid and crocin. All amino acids and crocin used in this study showed a quenching effect on the lumiflavin triplets. Further, it was determined whether the fitting models are suitable for these kind of measurements by simulating the decay of lumiflavin with and without any quencher. More studies on the fitting models have to be done to be able to get reliable results.

Yara Glomfjord is the north most production facility of compound fertilizer in the world and produces annually about 500 000 tons NPK and 200 000 tons CN. The general energy system of the process plant utilizes steam as the main energy carrier for the entire production site. Yara Glomfjord has today a general lack of steam, and steam is produced in EGA boilers approximately 75% of operational time to cover all heating tasks. The main objective of this Master thesis is to analyze energy flow in in the factory to identify energy saving potential, and later to suggest improvements for the CN-evaporator system in order to retire the use of EGA boilers and supply excess heat for other heating tasks in the factory.First off analysis was made on general energy flows in the factory. This was done in order to reveal potential for energy savings and to clarify which paths to choose for further heat integration. The result of the analysis shows that latent heat flows are of far greater importance than sensible heat flows to the general steam balance at Yara Glomfjord. It was also identified that the large potential for latent heat recovery lies within the evaporator equipment.Next up this text suggests investment in evaporator equipment in order to integrate latent heat, so that the overall steam consumption goes down. Three different suggestions were presented and analyzed in detail in the document: CN-Evaporator System Design. The most proving suggestions are new equipment coupled in cascade with old evaporators or a new independent MVR evaporator in front of old solution. Both suggestions are found to retire EGA boilers completely and also supply excess heat for other heating tasks. This text recommends one of these two suggestions.To suggest new improvements in the CN-evaporator system Epcon Evaporation Technology AS were involved. Testing at Epcon’s facilities in Trondheim indicate a new possibility. For the suggested retrofit cascade evaporation system, submergence of boiling pressure is possible. These findings supports the recommendations from this text to invest in a new evaporator coupled in cascade with the old solution with submergence of boiling pressure. In this way the energy savings in question can be implemented with only a small investment and almost no energy cost in a vacuum pump.As a huge potential for energy savings was found possible at reasonable cost and at a manageable technical level, the findings of this Master thesis hopefully settles the steam issues of the Yara Glomfjord compound fertilizer plant once and for all.In light of the late findings of this project, with the possibility of submergence of boiling pressure a hint is also sent to Yara Porsgrunn. As a great role model for Yara Glomfjord they utilize latent heat, but at the cost of expensive compressor work and not with submergence of boiling pressure which this text clearly states to be the superior technology.

In the present study the wake behind a scaled; Horizontal Axis Wind Turbine (HAWT) has been investigated. The experiments were performed at the Department of Energy and Process Engineering, at the Norwegian University of Science and Technology, NTNU. The turbine was installed in the wind tunnel at the department and measurements were performed at several distances behind the turbine to examine the development of the flow. A five-hole pitot probe was applied as measurement instrument. The instrument made it possible to calculate both size and direction of the velocity components.Through the experiments, characteristic curves of the turbine and grid measurements over the cross-section of the wind tunnel, were obtained. The power and thrust coefficients were measured against the local velocity ratio at the tip of the blade, the 'Tip Speed Ratio' (TSR). The power coefficient had a peak at TSR=5,5. The maximum value at this point was 0,45. The highest measured thrust coefficient was 1,15, achieved at TSR=10,3. During the experiments the turbine operated at optimal conditions, at the highest obtained power coefficient.Measurements behind the turbine found that the axial velocity distribution developed as expected. A significant velocity deficit was measured in the wake behind the turbine, which gradually decreased with increased distance to the turbine. Due to the presence of the hub and tower, the middle of the wake was characterized by disturbances. Moving down the wake the profile got more symmetric. The tangential profile was almost symmetric about the origin, right behind the turbine, but drifted to the left at increased distance downstream. Contribution from the tangential components were gradually reduced further down the wake.The tower shadow moved with the rotation of the wake, in clockwise direction, as a region of lower velocities than the prevailing wake. Further downstream the tower shadow merged with the surrounding wake.The rotational axis relocated in the wake behind the turbine. Downstream, measurements showed that the center of rotation moved to the left of the origin. To investigate if the tower was responsible for the experienced downshift, an additional tower was mounted to the tunnel roof, above the turbine. The additional tower created symmetry about the hub and gave a symmetric development of the flow field. Thus, it was concluded that the tower was responsible for the relocation of the rotational axis.

Oppgaven forsøker å vise den systemresponsen som er særegen for konvensjonelle tiltak og blå-grønne tiltak. Dette er aktuelt på Brøset bydel som en del av ”Fremtiden byer” prosjektet og skal bygges om til boligområde. MIKE URBAN og MIKE 21 er benyttet til å lage en konseptuell modell.Ved å sammenligne sommer- og vinterforhold, i tillegg til ulike gjentaksintervaller (1, 20 og 100år), vil kurver for videreført vannmengde gi et inntrykk av tiltakenes effekt. Dette gir beslutningsstøtte for Kommunalteknikk når de vurderer endringer i kommunens VA-Norm. Resultatene viser mer enn halvering av maksimal vannføring for alle forhold ved å velge fordrøyning eller blå-grønne tiltak fremfor konvensjonelle tiltak. Fordrøyning krever store sentraliserte volumer, mens blå-grønne tiltak på hver eiendom krever mange små og desentraliserte tiltak.

Sperre AS produserer i stor grad hele ROV konstruksjonen sin i aluminiumslegeringen AA6082-T6. Dette er et velegnet materiale for oppgava, men med noen mangler.Denne oppgava fokuserer på elektronikksylindrene til ROV-en, disse er per idag produsert i den ovennevnte aluminiumslegeringa. Man vil i framtida ned på store havdyp, ned mot 6000 meter. Når man skal så dypt vil disse elektronikksylindrene påføre konstruksjonen mye vekt og volum, både direkte pga større masse aluminium og indirekte ved at man trenger mye oppdriftsmateriale.Ved å benytte seg av kompositt og egna produksjonsmetode vil man kunne produsere samme tanken, med svært mye bedre egenskaper. I denne oppgava er det sett på metall-innerforing for spinning av kompositt på utsida og derfor oppnå ønska styrke, samt generelt design av sylinderen. Det er også foreslått design uten innerforing, men da produsert ved hjelp av kompositt-duk. Hvilket materiale som er best egna til innerforing og hvilken kompositt som har de beste egenskapene er også vurdert.Som deloppgave er det utført mekanisk testing på sveist aluminiumslegering for å verifisere DNV standardencite{DNV271}, samt vurdere om man ved forenkla varmebehandling kan gjenopprette noe av styrken til metallet.