Different attempts have been made to facilitate successful operation of Wastewater Pumping (WWP) system. The WWP units which are already existed in different parts of the world have been studied to identify its success, failure and different parameters associated with its suboptimal performance. The performance of WWP depends on three parameters namely pump, hydraulics, control system and pump station. These parameters are interdependent and must be carefully matched to achieve efficient WWP system. Nowadays the scenario has changed where organizations has started looking increasingly at the total cost of ownership, another way of saying Life Cycle Cost Analysis (LCCA) and recognizing the need to get most out of their equipment purchase. The master thesis includes theory part which describes the different parameters associated with WWP unit especially focusing on Xylems WWP system. This thesis is an attempt to help companies to know how LCCA could be productive management tool in order to minimize maintenance cost and maximize energy efficiency The study reported in this thesis work has been conducted to shed light over the use of Life Cycle Cost Analysis in WWP system. The current study tries to suggest and assess an adopted approach to ensure successful and efficient operation of WWP system with lowering energy demand and decrease in maintenance cost. Initial cost, Maintenance cost and Energy costs are important issues in the operation of WWP system since they are responsible for total cost over time. Therefore, description of each cost, formulas necessary for LCC calculations, data and survey structure, material and energy flow has been described. This work also aims to provide an extensive literature review, different survey and data collection techniques, analysis of collected data, statistical modelling, customer interaction by questionnaires and an interview with experts were used. LCC calculations were used to support the design and selection of most cost-efficient WWP system. Therefore, the given thesis work is an attempt to achieve better functional performance, improve existing design principles associated with WWP System, contribution to asses economic viability, support decision making to enhance operational quality to achieve efficient and successful WWP system.

Purpose: In this project work, the purpose is to perform an LCA as well as an LCC on two concept preschools, one with a wooden frame and one with a concrete frame. The result from the LCA is going to highlight, which of the building frames have the lowest environmental impact. In addition to the environmental impact, the project work  is going to include indoor climate together with energy use to get a broader view of the building’s overall performance. Method: This project work is in collaboration with Futurum Fastigheter i Örebro AB, where the authors have been instructed to perform an LCA on two concept preschools. One preschool has a wooden frame and the other has a concrete frame. The objective is to find out which of the buildings has the largest environmental footprint. In addition to this, the authors have evaluated an LCC together with an additional value tool. There are many tools to analyze the consequences from an environmental as well as an economic perspective. The report includes an LCA, LCC and an additional value tool. Result: The results show that the impact on CO2e/m2 for Bettorp was lower than Silva. Furthermore, the comparison between both preschools illustrated that Bettorp had lower emissions in all greenhouse categories except for carbon storage. The additional value tool portrays positive values for each preschool, although they differ. Conclusion: With the help of the software "One Click LCA" and "Visualisering och kvantifiering av mervärden vid energieffektivisering i offentlig sektor", the questionnaire has been answered and they all point to the wooden frame having a less environmental impacts along with a lower social cost of coal. The additional value tool was answered with the help of three employees at Futurum Fastigheter i Örebro AB. One of the participants concluded that there was no difference with regard to additional value between the preschools. The other two participants agreed that the preschool with a wooden frame provided a higher additional value compared to the other preschool.

I Sverige står bostadssektorn för mer än en tredjedel av landets energianvändning. Byggnader måste minska sin energianvändning för att således kunna uppfylla framtida lagkrav om maximal tillåten energianvändning, men också för att minska påverkan till global uppvärmning. Ytterligare en problematik som råder, däribland i Sverige, är bostadsbrist. Kommunala bostadsbolag står inför utmaningen att kunna bygga bostäder snabbt, billigt och miljövänligt för att minska bostadsbristen i landet. Ett sätt att studera två av tre hållbarhetsaspekter vid val av framtida bostadsbyggande är att utföra en livscykelanalys (LCA) och livscykelkostnadsanalys (LCC) kring de tilltänkta husen. LCA:er indikerar vilken miljöpåverkan en produkt förorsakar under dess livslängd. LCC:er avser att studera vilka kostnader produkter ger upphov till under en given analysperiod. Det svenska kommunala bostadsbolaget Stångåstaden AB står inför utmaningen kring bostadsbrist och vill bygga hållbara bostäder. Bostadsbolaget har önskat en jämförande LCA och LCC av två verkliga flerbostadshus som de genom ramavtal kan upphandla, detta är utgångspunkten för denna studie. Den ena byggnaden har stomme av betong, den andra har stomme av trä. Husen är tänkta att placeras i utkanten av Linköping, Sverige. Studien har valt att analysera miljöpåverkan från husens olika livscykelfaser samt kostnader över analysperioden 50 år. Utöver detta studeras även vilka energieffektiviseringsåtgärder (EEÅ) till byggnaderna som är optimala att genomföra för att öka den termiska prestandan hos huskonstruktionerna. Från litteraturen finns det relativt få studier som kombinerar både LCA och LCC för vanligt förekommande hustyper i städer. I dess standardfall påvisade resultatet från LCA:n att huset med betongkonstruktion hade något lägre påverkan i sex av sju studerade miljöpåverkanskategorier, jämfört med flerbostadshuset i trä. Resultatet skilde sig lite åt då annan typ av indata användes. Vad gäller kostnader under husens livslängd var huset i trä ungefär 20 % dyrare jämfört med huset med betongkonstruktion. Trots annan typ av indata var träkonstruktionen dyrare än betongkonstruktionen. Med en kalkylränta på 7,5 % var det inte lönsamt att genomföra EEÅ för husen, med halverad kalkylränta blev det dock lönsamt att tilläggsisolera krypgrunden i huset med trästomme. Fler studier behöver utföras för att generalla slutsatser ska kunna dras kring vilket konstruktionsmaterial som är mest hållbart. Denna studie baseras på två specifika fall. Samma resultat kan eventuellt inte förväntas för andra byggnader med stomme i betong och trä. / The residential sector accounts for more than a third of the energy use in Sweden. To reduce the energy use of buildings is a necessity in order to meet future regulationof maximum allowable energy, but also important to reduce the impact on global warming. Another complexity arising in Sweden is the shortage of accommodation. Municipal housing corporations face the challenge of constructing residences fast, cheap and with concern of environmental effects in order to reduce the shortage of accommodation. One way of assessing two of the three aspects of sustainability when looking at future construction of residential buildings is to carry out a Life Cycle Assessment (LCA) and a Life Cycle Cost Assessment (LCCA). An LCA can indicate what kind of environmental impact a product causes over its lifetime and the LCC allows for assessing what types of costs are associated with the product. For the municipal housing corporation Stångåstaden AB the shortage of accommodation is a reality and their mindset is sustainable construction of residences. This study was conducted upon request from Stångåstaden who wanted a comparative LCA and LCCA between two prefabricated multi-residential buildings that are available to them through a framework agreement. The first building has a concrete foundation and the second one is made of wood. The houses are planned to be placed at the outskirts of Linköping, Sweden. The focus of this study has been to comparatively assess the environmental impact from the different life cycle phases and the economic costs of the two buildings during a time period of 50 years. Moreover, the thesis also analyze the optimal retrofit strategy for the buildings in order to find the optimal (lowest) life cycle cost. Furthermore, the current literature has conveyed relatively few studies that combine both LCA and LCC methodology for house types that are common in most towns. The result from the LCA indicated that the house with concrete construction had a little less impact in six of the seven studied environmental impact categories compared to the house made of wood. The result differed slightly when the input data were changed. Regarding the LCCA the house made of wood was roughly 20 % more expensive than its concrete counterpart. Changing the input data revealed no difference in the result. With an interest rate of 7,5 % no retrofits were profitable for either building, however reducing the interest rate to half its original value made it cost optimal to increase the floor insulation for the house made of wood. More studies should be conducted to be able to draw general conclusions regarding which construction material that is the most sustainable. This thesis is based on two specific and real cases. The same result could possibly not be expected from other studies comparing buildings with concrete and wood construction.

Silicon Carbide (SiC) is a wide-bandgap (WBG) semiconductor materialwhich has several advantages such as higher maximum electric field, lowerON-state resistance, higher switching speeds, and higher maximum allowablejunction operation temperature compared to Silicon (Si). In the 1.2 kV - 1.7kV voltage range, power devices in SiC are foreseen to replace Si Insulatedgatebipolar transistors (IGBTs) for applications targeting high efficiency,high operation temperatures and/or volume reductions. In particular, theSiC Metal-oxide semiconductor field-effect transistor (MOSFET) – which isvoltage controlled and normally-OFF – is the device of choice due to the easeof its implementation in designs using Si IGBTs.In this work the reliability of SiC devices, in particular that of the SiCMOSFET, has been investigated. First, the possibility of paralleling two discreteSiC MOSFETs is investigated and validated through static and dynamictests. Parallel-connection was found to be unproblematic. Secondly, drifts ofthe threshold voltage and forward voltage of the body diode of the SiC MOSFETare investigated through long-term tests. Also these reliability aspectswere found to be unproblematic. Thirdly, the impact of the package on thechip reliability is discussed through a modeling of the parasitic inductancesof a standard module and the impact of those inductances on the gate oxide.The model shows imbalances in stray inductances and parasitic elementsthat are problematic for high-speed switching. A long-term test on the impactof humidity on junction terminations of SiC MOSFETs dies and SiCSchottky dies encapsulated in the same standard package reveals early degradationfor some modules situated outdoors. Then, the short-circuit behaviorof three different types (bipolar junction transistor, junction field-effect transistor,and MOSFET) of 1.2 kV SiC switching devices is investigated throughexperiments and simulations. The necessity to turn OFF the device quicklyduring a fault is supported with a detailed electro-thermal analysis for eachdevice. Design guidelines towards a rugged and fast short-circuit protectionare derived. For each device, a short-circuit protection driver was designed,built and validated experimentally. The possibility of designing diode-lessconverters with SiC MOSFETs is investigated with focus on surge currenttests through the body diode. The discovered fault mechanism is the triggeringof the npn parasitic bipolar transistor. Finally, a life-cycle cost analysis(LCCA) has been performed revealing that the introduction of SiC MOSFETsin already existing IGBT designs is economically interesting. In fact,the initial investment is saved later on due to a higher efficiency. Moreover,the reliability is improved, which is beneficial from a risk-management pointof-view. The total investment over 20 years is approximately 30 % lower fora converter with SiC MOSFETs although the initial converter cost is 30 %higher. / Kiselkarbid (SiC) är ett bredbandgapsmaterial (WBG) som har flera fördelar,såsom högre maximal elektrisk fältstyrka, lägre ON-state resitans, högreswitch-hastighet och högre maximalt tillåten arbetstemperatur jämförtmed kisel (Si). I spänningsområdet 1,2-1,7 kV förutses att effekthalvledarkomponenteri SiC kommer att ersätta Si Insulated-gate bipolar transistorer(IGBT:er) i tillämpningar där hög verkningsgrad, hög arbetstemperatur ellervolymreduktioner eftersträvas. Förstahandsvalet är en SiC Metal-oxidesemiconductor field-effect transistor (MOSFET) som är spänningsstyrd ochnormally-OFF, egenskaper som möjliggör enkel implementering i konstruktionersom använder Si IGBTer.I detta arbete undersöks tillförlitligheten av SiC komponenter, specielltSiC MOSFET:en. Först undersöks möjligheten att parallellkoppla tvådiskretaSiC MOSFET:ar genom statiska och dynamiska prov. Parallellkopplingbefanns vara oproblematisk. Sedan undersöks drift av tröskelspänning ochbody-diodens framspänning genom långtidsprov. Ocksådessa tillförlitlighetsaspekterbefanns vara oproblematiska. Därefter undersöks kapslingens inverkanpåchip:et genom modellering av parasitiska induktanser hos en standardmoduloch inverkan av dessa induktanser pågate-oxiden. Modellen påvisaren obalans mellan de parasitiska induktanserna, något som kan varaproblematiskt för snabb switchning. Ett långtidstest av inverkan från fuktpåkant-termineringar för SiC-MOSFET:ar och SiC-Schottky-dioder i sammastandardmodul avslöjar tidiga tecken pådegradering för vissa moduler somvarit utomhus. Därefter undersöks kortslutningsbeteende för tre typer (bipolärtransistor,junction-field-effect transistor och MOSFET) av 1.2 kV effekthalvledarswitchargenom experiment och simuleringar. Behovet att stänga avkomponenten snabbt stöds av detaljerade elektrotermiska simuleringar för allatre komponenter. Konstruktionsriktlinjer för ett robust och snabbt kortslutningsskyddtas fram. För var och en av komponenterna byggs en drivkrets medkortslutningsskydd som valideras experimentellt. Möjligheten att konstrueradiodlösa omvandlare med SiC MOSFET:ar undersöks med fokus påstötströmmargenom body-dioden. Den upptäckta felmekanismen är ett oönskat tillslagav den parasitiska npn-transistorn. Slutligen utförs en livscykelanalys(LCCA) som avslöjar att introduktionen av SiC MOSFET:ar i existerandeIGBT-konstruktioner är ekonomiskt intressant. Den initiala investeringensparas in senare pågrund av en högre verkningsgrad. Dessutom förbättrastillförlitligheten, vilket är fördelaktigt ur ett riskhanteringsperspektiv. Dentotala investeringen över 20 år är ungefär 30 % lägre för en omvandlare medSiC MOSFET:ar även om initialkostnaden är 30 % högre. / <p>QC 20170524</p>