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Thermal energy is an important resource for many industrial processes and is usually produced by combustion of hydrocarbon fuels with air. These processes could beneficiate from the use of oxygen-enhanced combustion (OEC), whose benefits (pollutants emissions reduction, fuel savings, productivity increase and volumes reduction) are already known. However, low costs oxygen production is still a challenge as the currently most used technique, cryogenics, is very energy consuming and costly. So, the present work proposes the thermodynamic analysis of two different techniques for production of oxidant required for the OEC process, the first one including air separation by polymeric membrane and the second one by PSA. Both systems were simulated on the software EES. Results show an increase of the energetic efficiency in both of the systems (from 22% to 58% in the membrane case and 66% in the PSA case) and of the exergetic efficiencies (from 18% to 48.5% and 54% respectively). A reduction of more than 60% of specific pollutants emissions was shown. The assessed techniques were shown to be energetically more attractive than cryogenics for small plants, the size limit depending on operating conditions.

Electricity access is widely recognized as a driver of development. The Brazilian government has incorporated this principle into its national rural electrification program, Luz Para Todos (LPT – Light for all), which has already benefited more than 14 million people in the country since its inception in 2003. But a different electrification model is required if remote areas in the Amazon region are to fully benefit from the program. In general, LPT has been implemented through a grid-based technology. However, the program has been less successful in providing electricity access in the Amazon region. In this region, about 24% of the rural population has no access to electricity. Key challenges are related to the exhaustion of the grid-extension model in isolated areas.  Extending the grid in these areas is neither realistic because of the local topography and natural conditions, nor cost-effective because expensive investments would be required to benefit a small number of citizens with low income and consumption rates. This study suggests an adapted LPT model for delivering electricity access in isolated areas of the Amazon region. In particular, the study offers a policy maker perspective and details the specific needs of isolated communities. It was developed in the form of a case study and included a variety of data sources, gathering techniques and analysis approaches, including an extensive literature review, the collection of in-situ evidence through direct observations and semi- structured interviews. Conclusions draw attention to the need for more local and site-specific solutions. Three issues will be decisive in achieving universal, reliable and affordable access to electricity in the Amazon region. Firstly, harmonization with the regional context is essential as the Amazon is a vast and unique environment. Secondly, there is need for adapting the existing institutional structures to appreciate the conditions and specific needs of rural populations in the Amazon region. Thirdly, securing financial resource allocation and distribution will be decisive in a LPT model aimed at universal electrification in the Amazon. / <p>QC 20120531</p>

Många butiker i glesbygden har tvingats lägga ned på grund av hård konkurrens från större butiker i städer och handelscentrum. De har dock ofta en samhällviktig roll som exempelvis ombud för apotek och post och en nedläggning bör om möjligt undvikas. Minskade energikostnader resulterar i att butikers chanser att överleva ökar. Projektets syfte var att föreslå åtgärder som kan reducera energianvändningen i fyra butiker i Stockholms skärgård. En energimodell för butikerna utvecklades för att simulera energianvändningen samt effekter av åtgärder, enskilt och i paket. För åtgärdspaketen bedömdes lönsamheten genom en livscykelkostnadsanalys. Statistik visar att den enskilt största energiposten i en butik är butikskylan (kyl- och frysdiskar samt kylrum), vilket bekräftas av resultat från simuleringarna av butikerna. Därför fokuserade åtgärdsförslagen på detta, men även åtgärder inom andra områden föreslogs. Många åtgärdsförslag var möjliga och de två med störst energibesparingspotential var installation av lock och dörrar på kyldiskar samt centralisering av kylsystemet. Även solelsproduktion visade bra resultat för reducering av köpt energi. Resultaten visar att vinsten av en energieffektivisering avgörs av faktorer som energianvändningen från början, den förväntade elprishöjningen och butikens utförande. I de butiker som undersöktes var energianvändningen låg. Detta i kombination med höga investeringskostnader gav långa återbetalningstider för många av åtgärdspaketen och möjligheten till bidrag kan därför spela en avgörande roll för att realisera effektiviseringarna. Åtgärderna för energibesparingar var dock många och i småbutiker med en högre elanvändning är energieffektiviseringspotentialen större.

Magnetic cooling is an emerging refrigeration technology with potential to surpass the performance of vapour compression devices. It has been successfully applied in the cryogenic temperature ranges, where magnetic cooling gas liquefiers surpass the performance of conventional liquefaction systems. Magnetic refrigeration technology is based on the magnetocaloric effect, a characteristic present in all magnetic materials and alloys. In magnetic thermodynamic cycles, magnetization of a magnetocaloric material is equivalent to the compression of a gas, while demagnetization is equivalent to expansion of a gas, with a subsequent diminution of the entropy. In this thesis, the applicability of this technology to the domestic environment is reviewed. First, the thermodynamics of magnetic refrigeration are explored. Then, a comprehensive review of magnetocaloric materials suitable for use at room temperature is presented. To ascertain the state of the art, the most relevant prototypes and their performances have been described. Concluding the documentation, a survey on the existing mathematic models has been performed, that provided the foundation to create a Matlab model of a magnetic refrigeration device. To gain greater insight on the internal working of these devices, a representative room temperature cooling device has been modelled, and used to simulate a magnetic refrigerator and room air conditioner. Its performance has been analysed and compared with that of vapour compression devices. Also, the influence of parameters such as magnetic field applied, temperature span, refrigerant fluid and different regenerator configurations has been investigated.

This study aims to evaluate how an electrification of heavy vehicles can be realized in practice on Gotland to promote the development of renewable energy and gain an understanding of how the energy system should be developed. A case study has been carried out at Roma Grus, a haulage company who has used an electric truck within their business as a part of a pilot project led by Ecoloop AB. The case study includes an evaluation of the pilot project and also a comparison between diesel and electric trucks based on the haulier's transports. The results show that the vehicle in the pilot project is difficult to apply to Roma Grus since it is not adapted for the business's long, irregular and high-consumption routes. Both higher battery capacity and charging power and an increased charging infrastructure are required. An electrification of the haulier’s transports would lead to higher investment costs but cheaper fuel costs and significantly lower emissions. This study also examines a full-scale electrification of Gotland's heavy diesel vehicles by investigating the impact on the energy system and greenhouse gas emissions. The results show that the energy demand from electric trucks would at most correspond to two percent of the current annual electricity consumption on Gotland. Regarding power consumption, fast charging of the vehicles will be a challenge due to lack of capacity in the electricity grid. However, if a full-scale electrification of heavy transport were to take place, the emissions could significantly reduce.

Absorption Heat Pumps (AHP) have been developed since the late 19th century. They enable to produce cooling and heating directly from a heat source, unlike Compression Heat Pumps that require mechanical work. In the context of scarcity of resources and global warming, the company Helioclim develops solar air conditioning using an Absorption Heat Pump. The heat is gathered at rooftop solar concentrators and powers an ammonia-water AHP. The present study proposes an EES model of Helioclim’s AHP allowing assessing its performances under various operating conditions. Another aspect developed is the Modelling of the whole system (from solar energy to the economic assessment) in order to find the best parameters to propose to a potential client. Regarding EES model, three existing EES examples of AHP have been used. Those models, ranging from the simple single-stage ammonia AHP to a more complex GAX-cycle, did not correspond exactly to the features of Helioclim’s cycle. Therefore, a new model has been built: the position of the GAX and its connections to the other heat exchangers have been adapted and a recirculation in the generator has been proposed in order to correspond to Helioclim’s design. The model obtained is then used to assess the improvement of the performances with the GAX. It is also compared to the available experimental data. In the present study, a software program representing the whole solar air conditioning system is also developed, integrating the previous EES model. The software program considers the solar energy gathered by the collectors and deduces the energy transmitted to the heat pump. The EES model is then used to assess the performances of the heat pump in the operating conditions, allowing determining the produced cooling and heating. An economic and energy synthesis is produced, summarizing effectively the parameters and economic advantages of the installation. This software program allows sizing an installation for a client much more quickly than before.

Examensarbetets syfte var att undersöka hur en byggnadsutformning påverkar den specifika energianvändningen. Det gjordes genom att simulera olika modeller av en förskola i IDA ICE. Underlaget för studien var förskolan Teleskopet som befann sig i stadsdelen Tavleliden i Umeå som illustrerades av modeller i IDA ICE för att sedan göra energibalansberäkningar. Fyra modeller med olika formfaktorer byggdes i IDA ICE. Ett enplanshus, ett tvåplanshus, ett treplanshus och ett fyrplanshus simulerades för att sedan bestämma hur formfaktor i förhållande till den specifika energianvändningen varierade. Modellerna som simulerades i IDA ICE behövde ha identiska brukarindata för att bara formfaktor skulle ändras. Således användes Boverkets föreskrifter om ändring av verkets föreskrifter och allmänna råd (2016:12) om fastställande av byggnadens energianvändning vid normalt brukande och ett normalår(BEN 2),Boverkets föreskrifter om ändring i boverkets byggregler (2011:6) -föreskrifter och allmänna råd; bfs 2020:4(BBR 29) och Umeå tekniska anvisningar från Umeå Kommun fastighet. Generellt sett visade det sig att enplanshus hade högre formfaktor jämfört med de andra modellerna. Studien visade att från en formfaktor på 2.4 till en formfaktor på 0.9 minskade den specifika energianvändningen med 4.9[ kWh/m2,år ]. Från samma studie kunde man också visa att om man ökade persontätheten från [ 0.33pers/m2,Atemp ] till [ 0.5pers/m2,Atemp ] kunde man spara 5.3[ kWh/m2,år ] på den specifika energianvändningen. Sammanfattningsvis är val av byggnadsutformning och persontäthet viktigt för att avgöra energiprestanda på byggnaden. Studien visar att ju lägre formfaktor samt högre persontätheten i en och samma byggnad påverkar byggnadens energianvändning med en total minskning på 5.3[ kWh/m2,år ]. / The purpose of the thesis project was to investigate how a building design affects it specific energy use. This was done by simulating different models of one preschool in IDA ICE. The basis for the study was the preschool Teleskopet which was located in the district Tavleliden in Umeå which was illustrated by models in IDA ICE and then make energy balance calculations.Four models with different form factors were built in IDA ICE. A single-storey house, a two-storey house, a three-storey house and a four-storey house were simulated to then determine the form factor in relation to the specific energy use varied. The models simulated in IDA ICE needed to have identical user data so that the form factor would change.The National Board of Housing, Building and Planning’s regulations on changing the board of directors were used, regulations and general guidelines (2016: 12) on the determination of the building energy use during normal use and a normal year (BEN 2), the National Board of Housing, Building and Planning’s regulations on changes in the National Board of Housing, Building and Planning’s building regulations (2011: 6) regulations and general guidelines; bfs 2020: 4 (BBR 29) and Umeå technical instructions from Umeå Municipality property were taken into consideration.In general, it turned out that single-storey houses had a higher form factor compared to those other models.The study showed that from a form factor of 2.4 to a form factor of0.9 it reduced the specific energy consumption by 4.9[ kWh/m2,year ]. The same study also showed that if one increased the person density from [ 0.33pers/m2,Atemp ] to [ 0.5pers/m2,Atemp ] resulted in a decrease of 5.3[ kWh/m2,year ] on the specific energy use. In conclusion,the choice of building design and person density is important to determine the energy performance of the building. The study showed that the lower the form factor and the higher the density of persons in one and the same building were, had an effect on the building’s energy use by one total reduction of 5.3 [ kWh/m2,year].

Detta examensarbete på C-nivå utförs på kemiindustri företaget Cambrex Karlskoga med fokus på energibesparing i en biologisk syrekrävandeprocess. Den biologiska processen sker i en bioreaktor, även kallad miniverket, vars volym är 1200 m3 där uppgiften är att reducera processvattnets TOC-halt innan det släpps vidare till industriområdets reningsverk. Syret tillförs till processen med komprimerad utomhusluft från en blåsmaskin via ett rörledningsnät på bioreaktorns botten. År 2021 förbrukade blåsmaskinen 680 MWh då dess kontinuerliga drift var 70% av dess maximala effekt. Syftet med detta arbete är att utreda om blåsmaskinens effekt kan minskas och ändå bibehålla en god TOC-reduktion i miniverket. Tre driftlägen utreds veckovis: 60%-, 55%- och 50% utav blåsmaskinens maximala effekt. Daglig provtagning och analys utförs av processvattnets TOC-, TSS-, PO4-, NH4-halt för att säkerhetsställa miniverkets funktion. Syremätning i den biologiska processen sker manuellt på fyra mätställen som utförs med en optisk syregivare. Under testperioden observeras att TOC-halten ökar medan syrehalten minskar i processvattnet när blåsmaskinen körs på lägre effekt. Dessa förändringar från miniverket påverkar dock inte det totala TOC-utsläppet från reningsverket till recipient, då miniverkets processvattenflöde är 5–10% av industriområdets totala flöde av processvatten. Därför är en sänkning av driftläget möjligt. När driftläget är 50% av blåsmaskinens maximala effekt blir energibesparingen 264 MWh per år. Metoderna för syremätning samt beräkning utav blåsmaskinseffekten kräver vidare utredning för att ge ett mer representativt resultat.

The aim of this thesis was to examine what impact future climate change and raised temperatures will have on current building design and how they can be adapted to the future climate change in terms of energy use, indoor temperature and thermal comfort by using passive solutions. This was carried out by a case study of a school building located in the Uppsala- Stockholm area, which was modeled in the energy simulation tool IDA ICE 4.8. The building was then compared in today’s (2020) climate to the future (2080) climate based on future weather data representing IPCCS’s RCP 8,5 scenario for the year of 2080, followed by an assessment of several climate adaption measures in the future climate. The result showed a future climate much warmer than the one today, with a monthly average temperature up to 1,5 degrees higher. This led to the school building being overheated for 703 hours during the period of April-September in the future climate, in comparison to 20 hours in today’s climate, regarding mean air temperature. The energy usage of the building showed a smaller heat demand for the 2080 climate but an added cooling demand that did not exist in the 2020 climate. Despite the added cooling demand, the building had a lower energy usage in total in the future climate.  In order to adapt the building to the 2080 climate, 10 passive measures were simulated individually as well as combined into two different packages of solutions, one large and one small. Overall, the results showed that no measure or package was enough to adapt the building in order to reach the current indoor climate requirements. For the building to keep the maximum mean air temperature at 26 degrees, an active cooling was needed as well. The measure keeping the lowest indoor temperature was the large package of solutions. Although, knowing that passive measures were not enough for the building to reach the current thermal requirements, looking at the total energy usage showed that the smaller package of solutions had the lowest annual energy demand of all measures. It had a marginally higher cooling demand due to fewer measures, but a significantly lower heating demand due to a less effective solar protection and a higher internal heating load.