In the future, new fuels will be sought to minimize the carbon footprint on Earth. With electric vehicles becoming a growing trend there is an annual increase in hybrid and electric cars, even electrified buses have become more convenient. The new electric vehicles will then be a load on the electricity grid when recharging is required, sometimes during the sensitive hours of the day where other power requirements are greater. The purpose of this thesis was to gain a deeper understanding of how the Swedish electricity grid is structured and also answer the questions if the area named Tomtebo will be able to handle an electrification of passenger cars, and also what the power forecast will look like. An excel model, developed by Sweco, is used for the calculations and later on there is an evaluation of this model if it can be applied to smaller areas and if any improvements can be made towards it. The electric car load on the electricity grid is based on three possible scenarios referred from a report by Sweco and using the excel model to calculate the power requirement of the three scenarios with different traffic works on electricity. Scenario one corresponds to today's electrification degree on traffic work, scenario two corresponds to double electrification degree on traffic work and in scenario three, a full electrification as well as a new traffic hierarchy with more public transports will be used, according to the report by Sweco, resulting in less power requirements for traffic. In all three scenarios, it is assumed that the electric car will be charged at night with a charging power of 2.3 kW, this corresponds to charging directly from power outlet. Tomtebo is a residential area that is being expanded and is expected to grow in the coming years and the population there are mostly younger families, which gives the probability of investment of a fossil-free passenger car increase. In order to estimate the proportion of electric cars for the area, Statistics Sweden and Region facts have been used to estimate the amount of cars at Tomtebo. In Umeå there is a total of 1,400 electric cars and 95 of these were likely to be at Tomtebo. Out of this amount there is plugin hybrids, PHEV, and pure electric cars, BEV, which gave a distribution 75/25 percent according to data from national statistics. With a known number of cars, an itinerary was required which could be probable around twenty kilometers. In the Excel model, values were applied for scenario one, which gave the power requirement for the 95 cars a total of 18 kW per hour. With a grid that has a total power up to 3.7 MW per hour then the cars' power requirements are a minimal burden towards it, furthermore an equivalent result came from both scenarios two and three. With these three results came the conclusion that with the amount of cars available there today no major load was done on the electricity grid and thus a greater number of cars were required. Umeå aims to reach 200,000 inhabitants by the year of 2050, which would then give Tomtebo 12,000 residents and this would result in an estimated 6,100 cars there. Of these with today's distribution there would then be 200 electric cars but since this scenario is so far ahead in the future it was assumed that all vehicles in 2050 would be an electric car, which then leads to it being fully electrified at Tomtebo. The 6,100 electric cars power provided 6 MW of total power demand for today's electricity grid, which means that it won’t work in the future. To find the breaking point for how many electric cars the gird can handle it was assumed that all Tomtebo's cars today, corresponding to 3,780 cars, would be electric cars and by moving the charge schedule to early morning, when the demand was much lower, the result gave that the grid could handle about that many cars. What is important to understand is that the electricity grid does not have a maximum ceiling for demand, but it all works about equilibrium where one strives for a consistent power balance on all iv hours of the day. If the consumers need more power then the electricity companies transfer it but an under-dimensioned infrastructure can put a stop to this which might be the case in the future. When the question whether Tomtebo's electricity grid can handle the load, the answer is that a full electrification of Tomtebo is entirely possible but that future investments are something that should be reviewed. This result from the excel model using the parameters and assumptions reflects the reality. The difficult thing about using the model in my opinion is the estimation of car numbers where in a city like Umeå where there does not exist any cameras or registers of which car type is moving where, which it does on others places, such as Gothenburg and Stockholm. Furthermore, there are thoughts about the design of the model as well also the question of the depth of battery but this is left out here but can be read under the relevant section. What controls how quickly a changeover from fossil-fueled to non-fossil vehicles is the result of instruments where subsidies and taxation come into focus, then of course laws and regulations. What makes it so difficult to estimate what the future will look like in theory is that tomorrow can have a new law leaving only non-fossil vehicles. / I framtiden eftersträvas nya drivmedel för att minimera klimatavtrycket på jorden. Med detta har eldrivna fordon blivit en växande trend där det syns en årlig ökning av personbilstyperna hybrid- samt elbilar, även elektrifierade bussar har blivit fler. De nya elfordonen kommer belasta elnätet då laddning krävs, ibland på dygnets allt känsligare timmar där övrigt effektbehovet är större. Syftet med detta examensarbete var att få en djupare förståelse i hur svenskt elnät är uppbyggt samt även besvara frågorna om området Tomtebo kommer klara av en elektrifiering av personbilar, och därtill, även hur effektprognosen för detta kommer se ut. För beräkningarna nyttjas en excelmodell framtagen av Sweco där en utvärdering om denna modell går applicera på mindre områden och om eventuella förbättringar kan göras. Elbilarnas belastning på elnätet ställs upp utifrån tre tilltänkta scenarion kopplade från en rapport av Sweco och med hjälp av excelmodellen beräknas effektbehovet eller belastningen fram. Excelmodellen behandlar dessa tre scenarion med olika trafikarbeten på el, där scenario ett motsvarar dagens elektrifieringsgrad på trafikarbetet, scenario två motsvarar dubbel elektrifieringsgrad på trafikarbetet och i scenario tre, en full elektrifiering samt också en ny trafikhierarki där man med hjälp av rapporten från Sweco menar att det kommer användas mer kollektivtrafik som resulterar i mindre effektbehov för trafiken. Det kommer i alla tre scenarion antas att elbilen laddas på natten av typen långsamladdning vilket då ger en laddningseffekt på 2.3 kW, detta motsvarar då laddning direkt från eluttaget. Tomtebo är ett bostadsområde som byggs ut och förväntas växa kommande år dessutom så är befolkningen där mest yngre familjer, med detta ges sannolikheten att chansen till en fossilfri personbil ökar. För att uppskatta andelen elbilar för området har SCB samt Regionfakta används och de gav att i Umeå finns totalt 1 400 elbilar och 95 av dessa uppskattades finnas på Tomtebo. Utifrån den mängden elbilar uppskattades mängden plugin hybrider, PHEV, samt rena elbilar, BEV, vilket gav en fördelning 75/25 procent. Med känt antal bilar krävdes en uppskattning av resväg vilket kunde uppskattas till två mil. I excelmodellen applicerades värden in för scenario ett vilket gav effektbehov för de 95 bilarna en total effekt på 18 kW per timme. Med ett nät som belastas med totala effekter upp mot 3.7 MW per timme så är bilarnas effektbehov en minimal belastning och ett likvärdigt resultat kom av både scenario två och tre. Med dessa tre resultat kom slutsatsen att med den mängd bilar som finns där idag kommer ingen större belastning ske på elnätet och därmed krävdes en större mängd bilar. Umeå har som kommunmål att 2050 uppnå 200 000 invånare vilket då skulle ge Tomtebo 12 000 invånare och detta skulle resultera i att det finns uppskattningsvis 6 100 bilar där. Av dessa med dagens fördelning skulle det då finnas 200 elbilar men då detta scenario är så långt fram i framtiden antogs att alla fordon år 2050 skulle vara en elbil vilket då leder till att det är fullt elektrifierat på Tomtebo. De 6 100 elbilarnas effekt gav 6 MW totalt effektbehov för dagens elnät vilket i framtiden mest troligt gör att det inte skulle klara av det. För att då finna brytpunkten för hur många elbilar som nätet klarar av antogs att Tomtebos alla bilar idag, motsvarande 3 780 stycken, skulle vara elbilar och genom att förflytta långsamladdningsschemat till tidigt morgon kunde ett resultat som tyder på att elnätet bör klara av ungefär så många bilar. ii Det som är viktigt att förstå är att elnätet inte har ett maximalt tak för belastning utan det hela handlar om jämvikt där man eftersträvar en jämn effektbalans på dygnets alla timmar. Behövs mer effekt hos konsument så överför elbolagen det men underdimensionerad infrastruktur kan sätta stopp för detta. På frågan om Tomtebos elnät klarar av belastningen så är svaret att en full elektrifiering av Tomtebo är fullt möjlig men att framtida investeringar är något som bör ses över. Angående excelmodellen kan man se att med de parametrar och antaganden som gjorts så ges ett resultat som speglar verkligheten. Det svåra med att använda modellen enligt min åsikt är uppskattandet av bilantal där det i en stad som Umeå inte existerar kameror eller kontroller kring vilken biltyp som rör sig var, vilket det gör på andra platser, exempelvis Göteborg och Stockholm. Vidare finns tankar kring utformning av modellen samt även fundering kring urladdningsdjup men detta tas inte upp här utan går att läsa under det relevanta avsnittet. Det som styr hur snabbt en omväxling från fossildrivna- till ickefossila fordon sker är till resultat av styrmedel där subventioner och beskattning kommer i fokus, sen självklart lagar och regler. Det som gör att det är så svårt att uppskatta hur framtiden kommer att se ut i teorin är att morgondagen kan ha en ny lag där endast ickefossila fordon skall existera.

One of the goals in this thesis is to make an energy balance for the new bathhouse in Kiruna. Another goal is to investigate whether it is possible to environmentally certify the building with bathhouse operations. Additional goal is to check whether the Upphandlingsmyndighetens sustainability criteria for bathhouses are possible to use when building bathhouses.  The background to this project is that Kiruna are getting a new bathhouse because the old one is to be demolished. What has been investigated in this project is the criteria for environmental certifications and whether a bathhouse business can meet those criteria. The indicator that has been of most interest is energy use. The energy balance was made through measurements and conversations with experts from the consultant company We group and by simulating the energy balance using the software VIP Energy. The work has resulted in an energy balance being created. A comparison is made between only the building and the building with a bathhouse activity. The environmental certifications were investigated, and they were found that none of the selected environmental certifications worked for the building with bathhouse activities since they use too much energy. The National agency for public procurement sustainability criteria for bathhouses generally works but need to be adjusted to be more useful.work but should be used as an aid until the criteria are completed. The energy balance showed that the bathhouse with operations had an energy consumption of 323.9 kWh / (m2, Atemp) in one year. The bath house without activity had an energy consumption of 44.3 kWh / (m2, Atemp) in one year. The building with bathhouse operations has an energy performance premiere energy of 351.5 kWh / (m2, Atemp) in one year and the building without bathhouse operations is 61.1 kWh / (m2, Atemp) in a year. The requirement from BBR on energy performance is 125.5 kWh / (m2, Atemp) in a year.

The AESCU-BIKE project is a cargo bike which has an inbuilt off-grid photovoltaic and a monitoring system. The off-grid photovoltaic system consists of a PV module, a lithium-ion battery, a lead acid battery, a charge controller and an electrical fridge. The PV module produces electrical energy which is used to cover the demand of an electrical fridge to supply enough cooling to store and transport pharmaceutical at temperature ranges between 0 °C and 8 °C within the city of Ulm. The monitoring system acquires, saves and plot information regarding the performance of the AESCU-BIKE such as voltages, currents, irradiance, temperatures, location and speed.  The first aim is to theoretically estimate the performance of the off-grid photovoltaic system during summertime and verify that the off-grid photovoltaics system components match. The second aim is to experimentally verify the theoretical estimation of the off-grid photovoltaic system performance during summertime by designing and implementing a monitoring system. The third aim is to visualize in real time information regarding the performance of the AESCU-BIKE. This information is used for an instant analysis of both transportation quality and correct functionality of the off-grid photovoltaic system. A user interface is programmed by using the software Nodered which can be installed in any smart device such as a computer, a smartphone or a Raspberry Pi.  Three different tests are performed to experimentally verify the theorical estimation of the off-grid photovoltaic system performance during summertime. Information such as PV module electrical energy production, fridge electrical energy demand, fridge temperature, ambient temperature, location and speed are plotted and analyzed using the software Excel.  After the results analysis, it is concluded that the monitoring system provides essential information to validate theoretical estimations and to deeply understand the behavior of the off-grid photovoltaic system. Regarding the PV module electrical energy production, losses related to the lack of a MPPT, not optimal PV module inclination angle and shading effect are clearly understood. Regarding the fridge electrical power demand, it is shown that the energy demand is highly related with the ambient temperature. The user interface makes the entire system more friendly. The instant visualization of the measurements helps the user to relate the physical phenomena with the system behavior.

One initiative to reduce greenhouse gas (GHG) emissions involves developing standards for GHG inventories. Companies and cities (regions) can use GHG inventories to compile and report their GHG emissions. Standards for corporate and city GHG inventories often claim that GHG inventories can be used for identifying emissions opportunities, building reduction strategies and setting, measuring and reporting emissions targets. Attributional emissions factors are generally used in corporate and city GHG inventories. For purchased electricity, heat and steam, this means using average emission factors for regional or national production of each energy carrier. Also contractual emissions factors can be used. Changes in emissions from affected production elsewhere are not included. For purchased electricity and district heating (DH), a GHG inventory can be improved by lowered purchases or by purchasing a different energy carrier. Furthermore, combined heat and power (CHP) technology can help reduce global GHG emissions in the supply and conversion of energy, as CHP production is more efficient than conventional separate production of electricity and heat. In CHP production, excess heat from electricity production is utilised for heating buildings, hot water, industry processes etc., either directly or through DH systems. This thesis analyses how emissions reduction measures based on corporate or city GHG inventories, carried out using GHG Protocol standards, affect global CO2 emissions when electricity or CHP-based DH is affected. The incentive of a GHG inventory to a company purchasing electricity and DH, and to a city regarding purchases and production of electricity and DH in its region, is analysed. This is done for GHG inventories conducted in a nation where electricity produced within the nation is regarded as CO2-lean (Sweden) and in a nation where it is more CO2-rich (Germany). The indirect incentive to the DH company to change its production, in order to improve the GHG inventory of its customers and of the city where the DH system is located, is also analysed. Consequential analyses are used to assess how global CO2 emissions are affected by changes in purchases or production of electricity and DH that are incentivised by the GHG inventories studied. These consequential analyses include changes in emissions from affected electricity production elsewhere. The results show that the strength of incentive to reduce purchase of electricity or CHP-based DH by a company or in a city can differ between GHG inventories and consequential analysis. This is most clear when electricity produced within the nation is regarded as CO2-lean (Sweden) while affected electricity production elsewhere is CO2-rich. For replacing purchases of CHP-based DH with electricity, or vice versa, the incentive in a GHG inventory can be the reverse of that in a consequential analysis. Moreover, the incentive to lower the use of electricity is lost when contractual emissions factors with zero emissions, such as renewable electricity guarantees of origin (RE-GOs), are used. In addition, purchase of electricity RE-GOs, which have a large surplus and no requirement of additionality, is less likely to cause a corresponding increase in production of renewable electricity. Furthermore, when the highest emission reduction per Euro invested is sought (e.g. when investment resources are limited), the investment ranking of a heat-only boiler and a CHP plant can differ depending on whether the focus is on improving a city GHG inventory or lowering global CO2 emissions. Moreover, if the DH company improves (reduces) the average emissions factor for DH, it improves the GHG inventory of its customers and of the city where they are located. In a DH system based on bio-fuelled CHP production, the average emissions factor for DH improves when CHP electricity production is lowered to the extent that production of heat at the oil-fuelled heat-only boiler (used for peak heat production) is minimised. However, according to consequential analysis, this would lead to an increase in global CO2 emissions. Based on the results of this thesis, it is concluded that measures which include changes in purchases or production of electricity or CHP-based DH can increase global CO2 emissions when based on how corporate or city GHG inventories in general value CO2 emissions of electricity and DH. It is therefore unfortunate that GHG Protocol standards for corporate and city GHG inventories advocate basing emissions reduction decisions on GHG inventories. There is nonetheless an obvious risk of reported and communicated GHG inventories being used as a basis for emissions reductions decisions. If the aim is actual reduction of global CO2 emissions, average or purchased emissions factors should not be used for purchased electricity and CHP-based DH when assessing, reporting or communicating the impact of companies and cities (regions) on CO2 emissions. Instead, a consequential approach should be used for climate evaluation of purchased electricity and DH. / Ett av många initiativ för att minska utsläpp av klimatpåverkande gaser är framtagandet av regelverk för klimatredovisningar. Klimatredovisningarna kan användas av företag och städer (regioner) för att sammanställa och rapportera om företagets eller stadens utsläpp av klimatpåverkande gaser. I regelverken för framtagande av klimatredovisningarna betonas ofta att klimatredovisningen kan användas för att identifiera var utsläppsminskningar kan göras, att utveckla strategier för att minska klimatpåverkande utsläpp samt för att sätta, mäta och följa upp mål för klimatpåverkande utsläpp. En klimatredovisning innehåller vanligtvis bokföringsvärden, vilket innebär att lokala genomsnittliga utsläppsfaktorer används för köpt el och värme. Även köpta utsläppsfaktorer kan användas. Klimatredovisningen inkluderar inte ändringar i utsläpp från produktion som påverkas någon annanstans. En klimatredovisning kan förbättras t ex genom att mindre energi köps eller genom byte av energibärare. För el- och värmeförsörjning kan kraftvärmeteknik bidra till minskade globala utsläpp av koldioxid (CO2), eftersom kraftvärmeproduktion är mer effektivt än separat produktion av el och värme. Vid kraftvärmeproduktion tas överskottsvärmen från elproduktionen tillvara för att värma byggnader, varmvatten, industriprocesser mm, antingen direkt eller via fjärrvärmesystem. I denna avhandling analyseras hur globala utsläpp av CO2 påverkas av åtgärder som påverkar förbrukning eller produktion av el och fjärrvärme, när beslut om sådana åtgärder baseras på ett företags eller en stads klimatredovisning, gjorda enligt Greenhouse Gas Protocols regelverk. Incitamenten i ett el- och fjärrvärmeköpande företags klimatredovisning och i en stads klimatredovisning analyseras. Detta görs för klimatredovisningar utförda i ett land där elproduktionen inom landet är CO2-mager (Sverige) och ett land med mer CO2-rik elproduktion (Tyskland). Dessutom analyseras de indirekta incitament som dessa klimatredovisningar ger till det lokala fjärrvärmeföretaget att ändra sin produktion för att förbättra sina kunders klimatredovisningar och klimatredovisningen för staden där fjärrvärmeverksamheten finns. Konsekvensanalyser görs för att beräkna hur olika åtgärder som stödjs av klimatredovisningarna påverkar globala CO2-utsläpp. I konsekvensanalyserna inkluderas också förändringar i utsläpp från påverkad elproduktion, även om den förändringen sker någon annan stans. Resultaten visar att styrkan i incitamentet att minska ett företags eller en stads inköp av el eller fjärrvärme kan skilja sig mellan en klimatredovisning och en konsekvensanalys. Detta är särskilt tydligt när klimatredovisningen görs i ett land där elproduktionen inom landet är CO2-mager (Sverige) medan den påverkade elproduktionen är CO2-rik. När det gäller utbyte av fjärrvärme mot el eller tvärtom kan en klimatredovisning ge motsatta incitament jämfört med den ledningen en konsekvensanalys ger. När köpta emissionsfaktorer med nollutsläpp för el används, t ex förnybara ursprungsgarantier, försvinner incitamentet att minska elanvändningen. Det är dessutom mindre sannolikt att ett köp av förnybara ursprungsgarantier för el medför motsvarande ökning av produktion av förnybar el, då överskottet av förnybara ursprungsgarantier för el är stort och additionalitetskrav saknas. När investeringsresurser är begränsade kan det vara av intresse att utvärdera vilken investering som ger mest reduktion av klimatpåverkande gaser per investering. Avhandlingens resultat visar att investering i hetvattenproduktion och kraftvärmeproduktion då kan komma att sinsemellan rangordnas olika, beroende på om målet är att förbättra stadens klimatbokslut eller om målet är att minska globala utsläpp av CO2. Om fjärrvärmeföretaget förbättrar (minskar) genomsnittlig emissionsfaktor för sin fjärrvärme, förbättras klimatbokslutet för deras kunder och för staden där fjärrvärmesystemet är beläget. Resultaten visar också att i ett fjärrvärmesystem, som baseras på ett bioeldat kraftvärmeverk och där olja används för efterfrågetoppar när det är som allra kallast, förbättras fjärrvärmens emissionsfaktor när elproduktionen i kraftvärmeverket minskas. Dock visar konsekvensanalysen att ett sådant agerande kan medföra ökade globala utsläpp av CO2. Baserat på resultaten dras slutsatsen att beslut om åtgärder, som påverkar köp eller produktion av el eller kraftvärmebaserad fjärrvärme, kan orsaka ökning av globala CO2-utsläpp om de baseras på de incitament ett klimatbokslut ger. Det är därför olyckligt att GHG Protocols regelverk för företags och städers klimatbokslut rekommenderar att klimatboksluten används för beslut som avser att minska utsläpp av CO2. Även om de inte rekommenderade detta, finns ändå en uppenbar risk att rapporterade och kommunicerade klimatbokslut används som bas för beslut om åtgärder som syftar till minskade utsläpp av CO2. Om syftet är minskade globala CO2-utsläpp bör genomsnittliga och köpta emissionsfaktorer inte användas för klimatvärdering av köpt el och kraftvärmebaserad fjärrvärme när ett företags eller en stads (regions) klimatpåverkan beräknas, rapporteras eller kommuniceras. För klimatvärdering av köpt el och fjärrvärme bör i stället en konsekvensbaserad metod användas.

This thesis looked at a biorefinery pilot plant that converted lignin in black liquor into biofuel. A heat/mass balance was made which was used to create a heat/mass balance for a theoretical large-scale plant. This then created the CAPEX for building the plant. OPEX for the largescale plant and income from sold biofuels was calculated and payback time found. This was done for three different cases with different flows and yield to optimize the plant. A sensitivity analysis was then made to find the most important parameters regarding CAPEX, OPEX and payback time.

CO2 separation plays an important role to mitigate the CO2 emissions due to burning of fossil fuels, and it is also of importance in biofuel production (e.g. biogas upgrading and bio-syngas purification and conditioning). The solvent-based absorption is the state-of-art technology for CO2 separation, where various solvents, e.g. amine solutions, Selexol (i.e. dimethyl ethers of polyethylene glycol), and propylene carbonate, have been introduced. However, these solvent-based technologies meet challenges such as high solvent degradation, high corrosion rate to equipment, high construction cost, high energy demand for solvent regeneration and high solvent make-up rate. Therefore, the development of novel solvents to overcome the challenges of the currently available solvents is essential. Recently, ionic liquids (ILs) have gained great interest as new potential solvents for CO2 separation, mainly due to their very low vapor pressure and relatively high CO2 solubility. In addition, ILs have lower corrosive characteristic, lower degradation rate and lower energy requirement for solvent regeneration compared with the conventional organic solvents. However, the main challenge of the application of ILs is their higher viscosity than the conventional solvents, which can be solved by adding co-solvents such as water. The overall objective of this thesis work was to develop low-cost IL based technologies for CO2 separation. To achieve this objective, the deep eutectic solvent (DES) of choline chloride (ChCl)/Urea with molar ratio 1:2 as a new type of IL was selected as an absorbent and H2O was used as co-solvent for CO2 separation from biogas. The conceptual process was developed and simulated based on Aspen Plus, and the effect of water content on the performance of ChCl/Urea for CO2 separation was evaluated. It was found that the optimal proportion of aqueous ChCl/Urea was around 50 wt% (percentage by weight) of water with the lowest energy usage and environmental effect. The performance of aqueous ChCl/Urea was further compared with the commercial organic solvents in this thesis work. The rate-based process simulation was carried out to compare the energy usage and the cost for CO2 separation from biogas. It was found that aqueous ChCl/Urea achieved the lowest cost and energy usage compared with other commercial solvents except propylene carbonate. The performance comparison proved that CO2 solubility, selectivity and viscosity were three important parameters which can be used as criteria in the development of novel physical solvents for CO2 separation. ILs with acetate anions normally show high CO2 solubility and selectivity, and the ILs with alkylmorpholinium as cations have low toxicity leading to lower environmental effect. Therefore, in this thesis work, a series of N-alkyl-N-methylmorpholinium-based ILs with acetate as counterpart anion were investigated, and water was added as co-solvent to adjust the viscosity. The CO2 solubility in these aqueous ILs was measured at different temperatures and pressures. It was found that the increase of alkyl chain length in the cation led to an increase of CO2 solubility of the ILs with the same anion. Aqueous N-butyl-N-methylmorpholinium acetate ([Bmmorp][OAc]) had the highest CO2 solubility, and it was selected to further carry out thermodynamic modeling and process simulation. The energy usage and the size of equipment of using aqueous [Bmmorp][OAc], aqueous ChCl/Urea, water, Selexol, and propylene carbonate for CO2 separation from biogas were compared. It was found that this novel IL mixing with water had better performance, that is, with lower energy usage and smaller size of equipment than the other solvents. This result suggests that using this aqueous [Bmmorp][OAc] has the potential to decrease the cost of CO2 separation.

No description available.

<p>This is a report written for an examination project C-level, on the subject of energy. The examination project is a product of the FVB Sweden AB (district heating bureau). It started with a meeting with Stefan Jonsson FVB Sweden AB, were he explained the content of the project, and from this a presentation of the problem was made. The problem that needed to be solved was how they could control the valves in the system to provide heating to everyone in the system. The valves are often oversized so the pump in the heating plant would have to be enormous to be able to provide enough flow to be sufficient, if everyone in the system had there valves fully opened.</p><p> </p><p>I came up with two solutions to the problem, one was a wireless network that could keep track of the valves and the other solution was an extra sensor that was placed on the radiator. The purpose for that was to open the valve if the temperature dropped more than one degree inside. With the help of a program called IDA it was calculated that, if the temperature drop five degrees, they would have sixteen hours at the heating power plant to open the flow before the sensor open the valves.</p><p> </p><p>After careful consideration I came up with the conclusion that the wireless network must be the best solution. Mostly because you can monitor all the clients in the system from the heating power plant and that will make it easier to discover faults and temperature differences.</p><p>Wireless networks is already a well tested solution in form of wireless controlled electricity meters so it shouldn’t be to much of a problem connecting these sensors to it either.</p>

<p>This thesis presents a study of the cooling process of a solid block performed by a turbulent air flow channel. The study focuses on the turbulent flow and its influence in the heat transfer of the block.</p><p>The first part of the thesis is an analysis of the different turbulent model and their adaptation on the necessities of this study. Once the turbulent model has been confirmed it makes a study of the behavior of the cooling process by CFD (Computational Fluid Dynamics), and an analysis of the numerical accuracy of this computational study.</p><p>When the procedure of the study of the cooling process is defined it proposes some different variations in the initial solution to improve this process. The study concentrates in variations of the turbulence and the geometry of the studied block.</p><p>Finally, the different improving are discussed analyzing parameters as the heat transfer, pressure drop, time consuming or energy consuming.</p>

<p>This project has been developed at the company Gavlegardarna. The companyowns a large part of the buildings of Gävle and two of them are the objective ofthe project. Gavlegardana is highly concerned about the environment; for thisreason, they cooperate on the subject with the energy management from theirtechnical department.</p><p>Gävle is one of the Swedish cities where the DH (district heating) network isdistributed, arriving to most of the dwellings, industries and commercialbuildings. As DH uses environmentally friendly sources of energy,Gavlegardana is introducing it in its buildings.</p><p>Electrical radiators and boilers were installed in the buildings when the price ofelectricity was more affordable than nowadays. The price of the electricity canbe considered 1,23 SEK/kWh while the DH price is 0,45 SEK/kWh.</p><p>Consequently, this is another reason why the objective of the company at thepresent time is to replace electrical space heating systems by means of districtheating.</p><p>The energy balance of the buildings is analysed in order to study their currentenergy situation. This entails the consideration of heat gains and lossesinvolved. The heat gains of the building are the heat from solar radiation whicharrives at the building trough the windows, the heat internally generated (bypersons, lighting and other devices) and the heat supplied. The heat losses are composed by the transmission trough walls and windows, the infiltrations, the heat used for hot tap water and the ventilation losses.</p><p>An important part of the work required to calculate the energy balance hasconsisted of the collection and organization of all the data (areas, types ofmaterial, electrical devices, lighting, number of employees, opening hours...).This data comes from the drawings of the buildings provided by the companyand from the information gathered during the visits to the installation. In addition, the ventilation flows were measured in-situ using the tools provided by Theorells.</p><p>Gavle Energi, the DH distributor company, has been contacted in order to fixthe cost and other details related to the district heating connection. The heatexchanger models, selected from Palmat System AB, are TP20 for Building Aand TP10 for Building B. TP20 provides 100 kW of heating and 0,4 l/s of hot tap water and TP10 provides 50 kW and 0,31 l/s respectively. The capital cost is 187500 SEK which includes the heat exchangers and the connection cost.</p><p>As the secondary circuit is not currently installed because the existing system iscomposed by electrical radiators, the installation of the piping network in thebuilding has been designed. The radiators’ power is calculated taking intoaccount the need of heat in each room which is estimated as the transmissionlosses. This need of heat calculated is higher than the energy currently supplied which means that the thermal comfort is not achieved in all the rooms of the buildings.</p><p>In spite of using more energy for space heating, the change of heat sourceentails a lower energy cost per year. The selected radiators are from Epeconand the investment cost (including the installation) is 203671 SEK. The brand of the selected pipes is Broson and the investment cost of the total piping system is 66000 SEK.</p><p>The initial investment of the new installation is 457171 SEK, considering the DHconnection, heat exchangers, radiators and pipes. If the initial investment istotally paid in cash by the company the payback will be fulfilled in 6 years. Incase of borrowing the money from the bank (considering an interest rate of 5%), two possibilities can be considered: paying back the money in annual rates over 15 years or 30 years of maturity. The paybacks are 11 and 8 years respectively.</p><p>After designing the DH piping system in the buildings, estimating the total costs of the investment and studying the project’s feasibility by suggesting different payment options, some possible energy savings are recommended.</p><p> </p><p>The first of the options refers to the transmission losses trough the windowswhose values’ are considerably high. Using a glass with a lower U-value, theselosses can decrease until 66% (with triple glass windows). Consequently, thepower required for space heating can also be reduced until 26%.</p><p>Regarding the ventilation, rotating heat exchangers are currently used, whichentails the problem of smells mixture detected by the users of the buildings. By changing them with flat-plate heat exchangers, the problem is solved and the efficiency is increased from 66% to 85%. The new heat exchanger cost is340387 SEK and it has a payback of 10 years.</p>