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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Energy Losses Study on District Cooling Pipes : Steady-state Modeling and Simulation

Calance, Marius Alexandru January 2014 (has links)
Distributionsförluster är en viktig faktor i fjärrenergisystem. Genom att optimera förluster i sådana system, kan både ekonomiska och miljömässiga aspekter uppfyllas. Tyvärr finns det ringa information om rörförluster i fjärrkylasystem. Föreliggande studie fokuserar på förluster i ett fjärrkylanät genom att både använda ett R-nätverk och FEM simuleringsmodeller. Ett R-nätverksmodell bestående av termiska konduktanser har utvecklats genom analytiska ekvationer och simuleringar med FEM har utfört för validering av modellen. Därefter har ett fjärrkylanätverk som konstrueras i Gävle, analyserats. Undersökningen omfattar 15 olika rördiametrar i tre utföranden (dubbelrör med två symmetriska och en osymmetrisk värmeisolering) och i tre förläggningsdjup (0,8; 2 och 4 meter) för en säsong om 7 månader (April t o m Oktober). Särskilt utreds ökningen av temperaturen hos framledningsmediet, där matningsrören förlagts i en å mitt i staden om en sträcka av 1 km. Den maximala förlusten under säsongen, bland alla rörkonfigurationer, motsvarar 2 % av den totala levererade energin. Slutligen konstateras att kombinationen av isolerad framledningsrör och oisolerade returrör verkar som en gångbar investering, ekonomiskt och tekniskt, men kan inte användas i hela nätet eftersom stora delar har redan byggts med oisolerade plaströr. R-nätverksmodellen, som visades vara effektiv och pålitlig i undersökningen, kan som beräkningsverktyg, framförallt för dimensionering och för att uppskatta energiförluster. / Distribution losses are a very important factor in district energy systems. By optimizing the losses in such a system, both economical and environmental aspects can be fulfilled. Unfortunately, there is few information regarding losses for district cooling systems. This study focuses on losses in district cooling networks by using both R-network and FEM simulation models. A R-network model composed of thermal conductances has been developed through analytical equations and simulations have been performed for validation. Afterwards, an in-progress construction project of a district cooling network from the city of Gävle, Sweden, is analyzed. The assessment consists of 15 pipe diameters in three configurations (two symmetric cases and one asymmetric), at three ground laying depths (0.8, 2 and 4 meters) for a duration of 7 months (April to October). A particular case in which the main distribution pipes from and to the plant are submerged in the city’s river for a distance of 1 km is investigated in order to estimate the temperature increase of the supply water. A maximum cooling loss below 2% of the total delivered energy during the season for any network configuration resulted from the calculation. Finally, the mixed pipes array seems to be a feasible investment both economically and technically but it cannot be used for the entire network spread since a part of the network has been already built with the non-insulated plastic pipes. The R-network model proved to be effective and reliable in the analysis which provides confidence that it can serve as a solid foundation for a calculation tool - primarily for design purposes and also for estimating energy loss.
12

Fjärrkyla på LKAB : Absorptionskylmaskiner, frikyla och dess begränsningar

Kruukka, Erik January 2020 (has links)
LKAB behöver kyla till sina processer för att kunna förädla järnmalm. Ökad tillgång på elektronik och efterfrågan på komfortkyla breder ut sig i samhället idag, vilket leder till ett ökat kylbehov. Flertalet gamla kylanläggningar på LKAB i Kiruna börjar uppnå sin livslängd och behöver ersättas med nya maskiner och ny teknik. Då är utbyggnad av fjärrkylanätet som idag levererar kyla till KK4, KA3 och SAK-labb/kontor extra intressant. Istället för att ersätta gamla kylmaskiner i andra byggnader med nya kan man ansluta sig till de berörda fjärrkyalnätet. Det är ett nät där absorptionskylmaskiner och frikyla tillgodoser kylbehoven vilket även är ett bra val ur en miljömässig synpunkt då man nyttjar spillvärme. Idag klarar detta system av att leverera kyla till nuvarande kunder men frågan är hur mycket mer man kan ansluta till samma nät och vart begränsningarna ligger. Tittar man bara på kylmaskinerna ska man kunna ta ut 3MW kyla vilket är tre gånger så mycket som levereras idag. Begränsningarna ligger således inte där utan det är i de olika kretsarna till/från kylmaskinerna. I denna studie har mätvärden bakåt i tiden varit nödvändiga då endast frikyla använts under tidsperioden då detta examensarbete har utförts. Problem med loggning av data, felinställda givare och avsaknad av mätare har gjort att konkreta beräkningar uteblivit. Denna studie får ses som ett första steg mot en eventuell utökning av kylnätet. Konkreta förslag på hur man ska komma vidare för att kunna utnyttja nuvarande kylanläggnings hela potential tas upp i rapporten. Kan man i framtiden bygga ut fjärrkylnätet skulle man minska elanvändningen och underhållskostnaderna då man får ett färre antal kylmaskiner. / To refine iron ore products cooling is needed at LKAB. The increase of electronic devices and comfort cooling leads to higher cooling demands everywhere in society. Many old cooling machines soon are going to reach the end of their life span and needs to be replaced at LKAB in Kiruna. The development of the current district cooling grid is therefore interesting. Instead of replacing old machines in other buildings with new ones they can be connected to the existing grid. It is consisting of two absorption machines and free cooling and delivering cooling to the buildings KK4, KA3 and SAK-lab/office. The energy to the machines came from waste heat which is good for the efficiency and for the environment. Today the cooling system can manage the demands but how much can be connected to the grid in the future and where the limitations is for the current cooling system has yet no answer. The capacity of the absorption cooling is about 3MW and it is three times more than what is delivered today. So, the limitations are not the installed capacity but instead the different circuits in and out to the cooling machines. In this study previous measurements were important because only free cooling was used during this project. Problems with sensors, logging data and missing flowmeter made it impossible to do concrete calculations. Instead this study is a first step in the right direction to development of the district cooling system well as suggestions for future work. If the grid can be used to full potential the power consumption and the maintenance cost will decrease which is good for the environment and the economy.
13

Fjärrvärmedriven Absorptionskyla : En ekonomisk undersökning av olika spetslösningar

Strömqvist, Bodil January 2021 (has links)
This independent degree project has been implemented on behalf of FVB Sverige AB in collaboration Sundsvall Energi AB with the initial purpose of mapping manufacturers of hot water driven absorption chillers. After that, several technical solutions are examined to manage the peak load of a theoretical object which cannot produce the cooling power required with only an absorptions chiller, due to limitations in the district heating supply. The market study has shown that the supply of absorption chillers with drive temperatures of 70–90˚C is limited to a few manufacturers. World Energy offers a unit with drive temperatures of 70 ˚C and efficiency (COP) of 0,4. Due to limitations of district heating flow, a unit with drive temperature of 85 ˚C and efficiency of 0,77 is chosen. The technical solutions are dimensioned for a building with a peak power of 264 kilowatt, where the required peak load ranges from 31 to 39 kilowatt. The technical solutions examined are a solar collector system, tap water heat exchanger, and a conventional compressor driven chiller. The solar collectors are dependent on location but use no refrigerants that are affected by the F-gas regulation. The tap water solution consumes large flows of tap water, but the installation is simple. The conventional chiller is not location dependent but uses ozone degrading refrigerants and has a high cost of operation. From an economic perspective the technical solutions are equally profitable with a present net value of approximately 500 000 SEK and pay-back of 13 years. The examination has also shown that the present value is one million crowns in sales of heat and building after a ten-year period. In conclusion the conventional chiller has the biggest prerequisites to be used as a standardised solution for buildings with a bigger cooling load. Based on the technical and economical conditions.
14

Kyllösning för kommersiell fastighet : Undersökning av olika alternativ för komfortkyla

Alsing, Anders January 2023 (has links)
Det här arbetets syfte är att ge förslag på ny kyllösning i en kommersiell fastighet. Den nuvarande lösningen innebär att kylan kommer ifrån tappkallvatten som spolas in i en värmeväxlare, den här lösningen är både dyr och har en negativ påverkan på vår miljö, fastighetsägaren är inte nöjd med detta och vill göra om systemet. Då det inte finns några direkta mätvärden från systemet förutom vattenförbrukningen så är effekt-och energibehovet en osäkerhet. Två driftfall har tagits fram där driftfall 1 och driftfall 2 har ett effektbehov på 80 kW respektive 130 kW. Utifrån driftfallen har effekt- och energiprofil tagits fram. Med hjälp av profilerna har en ny lösning tagits fram men med fyra olika metoder. Undersökningen tar upp lösningar med fjärrkyla, bergkyla, absorptionskyla och kompressorkyla. Fjärrkylan är idag inte ett möjligt alternativ då det fortfarande inte finns ett fjärrkylanät men diskussionerna pågår om ett sådant nät och på grund av detta är fjärrkyla med som en möjlig framtida lösning. Undersökningen visar att fjärrkyla inte är ett lönsamt alternativ, detta eftersom man behöver behålla nuvarande lösning fram till dess. Absorptionskyla är inte heller ett bra alternativ och det beror på det höga fjärrvärmepriset. Det visar sig att lösningen med bergkyla eller kompressorkyla är de bästa alternativen där en kompressordriven kylmaskin ses som den mest lönsammaste men ur en miljöaspekt är den det mindre bra även om den kylmaskin som används i denna undersökning använder sig av ett köldmedium med förhållandevis lågt GWP-värde. / This study’s purpose is to give suggestions of a new cooling system in a commercial building. The current system implies that the cooling come from tap cold water that flushes into a heat exchanger, this solution is both expensive and have a bad impact on the environment. The property owner isn’t satisfied with this and want to remake the system. There isn`t many measurement values that I can use to calculate the effect and energy needs for the building except the water consumption in the cooling system. Because of this uncertainty two cases have been used in this study. The first has an effect need of 80 kW and the other have an effect around 130 kW. From these two cases has an effect and energy profile been made from each of the two cases. With the profiles made, can a new solution be presented and in this study we have four different methods for the cooling system. An investigation has been made on district cooling, ground cooling, absorption cooling and compressor cooling. The district cooling isn`t possible today because it doesn’t exist but the local energy company having discussions about it and because of this, district cooling is a possible future solution. The study shows that to wait for a district cooling isn´t a profitable solution, neither is the solution with the absorption cooler, the absorption machine is being driven by district heat and the price is too high in Bollnäs. This study shows that ground cooling or compressor cooling are the best options in this case. The compressor cooling is the most profitable, but it has a downside in the environment perspective. All energy is based on electricity energy, and the refrigerant can affect the environment in a bad way if it´s a leak. But I should say that the cooling machine used in this study uses a refrigerant that has a relatively low GWP-value.
15

An economic comparison between two district cooling systems in Halmstad

Le, Alex January 2014 (has links)
The supply of cooling has increased significantly in recent years, the trend shows that the increase will continue one reason is that the standard of living has increased, but EU has also set a requirement that energy consumption must be better at the same time. With “better” means more efficient and environmentally friendly. District cooling today uses either chillers or naturally available cold sources such as deep sea water, lake water or cold air. Cold air is, of course, only available when the seasons permit it and the cold air is not available when comfort cooling is needed for e.g. offices. The only alternative for areas that do not have a cold water source nearby is to use chillers. The most common chillers today are compressor chillers and absorption chillers. The most interesting chiller for the energy and environmental company HEM in Halmstad, is the absorption chiller which is driven by heat. HEM has, during the summer, surplus heat produced in Kristinehed plant which they want to use, they also have an increased inventory of waste during the summer which they get from the municipality of Halland. This heat is, of course, qualified to be used in the making of cold. Absorption chillers is today, however, not as common as compressor chillers which are capable of dealing with most cooling capacities, from small to large, and simultaneously works more or less flawlessly. Most of today’s absorption chillers are of a few hundred kW and upwards while there are no absorption chillers for the smaller effects, they are also very expensive and can have problems with crystallization of the absorbent if the operation is handled incorrectly. But it’s also expensive when it comes to piping of district cooling networks depending on where the pipes are desired, for example if it is the middle of town or over a grass field. A fictional project of the area Sannarp is used for a case study in this thesis where one investment alternative was to extend the existing district cooling pipes and another alternative was to invest in absorption chillers to meet the company's cooling demand. The results were obviously much affected by the area's layout and the distance to the first company starting from the existing pipe. The company's cooling demand also affected the results and the first alternatives investment cost could only be competitive with alternative 2 because the distance was just of the right length. If the distance to the company had been shorter, then the cooling demand for the same company has had to be less. The conclusion of the project was still in the end that and expansion of the current district cooling network to the company was the most feasible and economically advantageous.
16

Potential for low temperature district heating system : Integrating 4th generation district heating system with existing technology

Kamal, Majd January 2017 (has links)
This project presents a feasibility study and an investigation of the potential for low temperature district heating system in Västerås. The investigation treats integrations possibilities for 4GDH (4th Generation District Heating) in Kungsängens area in Västerås, which is undergoing a large-scale building-up and construction.  The study is conducted for the company Mälarenergi AB. The advantages of 4GDH technology are identified and analyzed, where energy effectiveness and economic benefits aspects were concluded. Problems with existing technology and higher cooling demand expectations drive 4GDH to be an interesting and necessary technology in the future. Four Different integration solutions between old and new networks are presented, analyzed and discussed. Quantitative analysis conducted where initial cost for the four technical solutions were estimated and compared. The results show that low temperature district heating could lead to reduction in the initial cost for the network by using PEX instead of steel as pipe material. The results show also that one solution using heat exchanger as exchange stations has the lowest cost between the four solutions. The results show that the cost for the retention flow that is linked with 4GDH stands for 20%-30% of the total cost. The importance of the retention flow pipe is investigated using two physical models in OpenModelica and Excel, where simulations were conducted. It is concluded that it is possible to provide Kungsängen area with low temperature district heating without having the retention flow pipe. Three parameters were identified to be critical which are, geographical placement of the consumers, pattern variation for the heat demand and heat systems installed inside consumer’s buildings. The results show also that it might be critical to have a variate and optimized supply temperature for the area, depending on the demand. The simulations of a fictive area that could present a future heat demand for Kungsängen area shows that a temperature of 55°C is satisfying during winter season where the demand is high and a temperature between 60-65°C must be available during spring/autumn seasons and specially during summer. The variation depends directly on the temperature drop through the supply pipes to the consumers. The temperature drop is directly linked with water velocity inside the pipes. The losses increase during summer nights when the heat demand is low which lead to low water velocities.
17

Fjärrkyla i Sundsvall : Optimering av framledningskurva för akviferbaserad fjärrkyla

Unger, Oskar January 2019 (has links)
På uppdrag av Sundsvall Energi AB har FVB Sverige AB påbörjat en förstudie kring etableringen av fjärrkyla i Sundsvall. Produktionsmedlen i det planerade nätet kommer att innefatta frikyla från akviferen och en kompressordriven kylmaskin. Det övergripande syftet med projektet har dels varit att ta fram en optimal framledningskurva, samt att ta reda på i vilken utsträckning frikylan kan nyttjas innan kylmaskinen måste användas som spetsproduktionsmedel. Projektet har inledningsvis fokuserat på att undersöka hur klimatet och kylbehovet ser uti Sundsvall. Kylbehovet granskades utifrån sex befintliga byggnader som nyttjar dricksvattenkyld fjärrkyla i Sundsvall. Därefter undersöktes olika typer av klimatsystem för att utröna vad de har för krav på framledningstemperaturen. Det konstaterades att kylbatterier var den komponent som kräver lägst framledningstemperatur, varför kyleffektberäkningar utfördes på dem. Resultatet ur kylbatteriberäkningarna fick motsvara den av fjärrkylenätet avgivna kyleffekten vid varierande utomhustemperatur. Genom att väga den avgivna kyleffekten vid varierande framledningstemperatur mot det erforderliga kyleffektbehovet vid varierande utomhustemperatur kunde framledningskurvan ta form. Akviferen antas hålla en temperatur på omkring 7°C till 9°C året runt, men utgångspunkten i detta projekt har varit att den konstant är 9°C. Under de förutsättningarna har framledningstemperaturen kunnat bestämmas till att vara 11°C under större delen av året, men att den sänks vid en utomhustemperatur på omkring 21°C i varierande grad ned till 6°C vid utomhustemperaturen 25°C. Med hjälp av framledningskurvan kunde därefter frikylans täckningsgrad bedömas. Resultatet visar att om framledningens temperatur höjs med 0,5–1,0°C i distributionsnätet kommer kylmaskinen att behöva vara i drift under 159 timmar per år. Om istället uppvärmningen blir 1,5° eller 2,0°C kommer kylmaskinen behöva vara i drift under 233 timmar respektive 325 timmar. Sammantaget har samtliga av projektets konkreta och verifierbara mål besvarats. / On behalf of Sundsvall Energi AB, FVB Sverige AB has initiated a preliminary study on the establishment of a district cooling system in Sundsvall. The main source for the cooling will be cool water drawn from the aquifer and a compressor chiller. The main purpose of this project has both been to provide the optimal supply temperature of the cooling network at different outdoor temperatures, and to find out to what extent the cool water from the aquifer can be used by itself as the cooling source. The project was initially focused on examining the climate and cooling demand in Sundsvall. The cooling demand was examined on the basis of six existing buildings that uses freshwater district cooling, and different types of climatesystems were then examined to ascertain what their requirements for the supply temperature are. Cooling coil batteries were found to be the component that requires the lowest supply temperature; therefore, the cooling power calculations were relied on them. The outcome of the cooling coil battery calculations was presumed to correspond to the cooling power of the network itself. By comparing the cooling power of the coil batteries at different supply temperatures and the cooling demand at different outdoor temperatures the main supply temperature for the district cooling network took shape. The aquifer is expected to maintain a temperature of approximately 7°C to 9°C, but in this project the temperature is set to exactly 9°C. On those premises the supply temperature of the cooling network could be set to 11°C for most of the year, but with a reduction of the supply temperature at outdoor temperatures around 21°C. Subsequently the supply temperature is reduced to 6°C at the outdoor temperature 25°C. Via the supply temperature curve, the aquifer cooling coverage ratio could be assessed. The result shows that if the supply temperature is raised between 0,5°C and 1,0°C in the distribution network the compressor chiller will have to be in operation for 159 hours per year. If instead the supply temperature is raised 1,5°C or 2,0°C, the compressor chiller must be in operation for 233 hours and 325 hours, respectively. In summary, all the goals and targets of the project have been completed.
18

Metodologia para análise termoeconômica de sistemas de resfriamento distrital. / Thermoeconomic methodology for district cooling systems analysis.

Santos, Arthur Garuti dos 18 March 2019 (has links)
Com o constante desenvolvimento das áreas urbanas e aumento do consumo energético destinado a conforto térmico, um estudo foi realizado para formulação de uma metodologia de análise termoeconômica de sistemas distritais de resfriamento. O objetivo principal é descrever uma metodologia referente à implantação de sistemas distritais no Brasil, por sua vez, o objetivo secundário é aplicar a metodologia no estado de São Paulo, analisando as premissas utilizadas na metodologia. Primeiramente, apresentou-se uma visão geral e revisão de literatura dos sistemas de aquecimento e resfriamento distrital, indicando suas vantagens e desvantagens, bem como as diversas aplicações e desafios para sua implantação. Aplicações no cenário mundial foram expostas e analisadas, demonstrando que sua utilização em diversos países se estende por décadas. As principais vantagens observadas nas aplicações existentes estão relacionadas a maior eficiência energética e exergética global, redução das emissões de gases poluentes e confiabilidade do sistema. Por fim, a metodologia aplicada está apresentada em cinco etapas, de forma ordenada, baseando-se nas etapas de um projeto de sistemas distritais. Seu resultado é baseado em rotinas, simulações de processos e procedimentos de otimização, bem como aplicação de indicadores energéticos. Ao final das etapas e seu desenvolvimento matemático obtém-se um estudo preliminar de viabilidade da implantação de um sistema distrital. O estudo de caso apresentado aplica a metodologia para a cidade de São Paulo buscando descrever com detalhamento as premissas e etapas descritas. / The constant development of urban areas and increased energy consumption for thermal comfort encourage studies that formulate a methodology for thermoeconomic analysis of district cooling systems. The main objective is to describe a thermoeconomic methodology related to the implementation of district systems in Brazil. The secondary objective is to apply the methodology in the state of São Paulo, analyzing the premises used in the methodology. At first, an overview and literature review of district heating and cooling systems was presented, indicating their advantages and disadvantages, just as the various applications and challenges for their implementation. Applications on the world stage have been introduced and analyzed, demonstrating that their use in several countries extends for decades. The main advantages observed in the existing applications are related to global energy and exergy efficiency, reduction in greenhouse gases and reliability of the systems. Finally, the applied methodology is presented in five steps in an orderly manner based on the steps of a district system project. Its result is based on routines, process simulations and optimization procedures, as well as application of energy indicators. At the end of the steps and their mathematical development a preliminary study of the feasibility of the implantation of a district system is obtained. The present case study applies the methodology for the city of São Paulo and describe in detail the premises and steps.
19

INTEGRATED SYSTEM ARCHITECTURE DEVELOPMENT AND ANALYSIS FRAMEWORK APPLIED TO A DISTRICT COOLING SYSTEM

Akshay Satish Dalvi (9741170) 07 January 2021 (has links)
<div>The internal and external interactions between the complex structural and behavioral characteristics of the system of interest and the surrounding environment result in unpredictable emergent behaviors. These emergent behaviors are not well understood, especially when modeled using the traditional top-down systems engineering approach. The intrinsic nature of current complex systems has called for an elegant solution that provides an integrated framework in Model-Based Systems Engineering. A considerable gap exists to integrate system engineering activities and engineering analysis, which results in high risk and cost. This thesis presents a framework that incorporates indefinite and definite modeling aspects that are developed to determine the complexity that arises during the development phases of the system. This framework provides a workflow for modeling complex systems using Systems Modeling Language (SysML) that captures the system’s requirements, behavior, structure, and analytical aspects at both problem definition and solution levels. This research introduces a new level/dimension to the framework to support engineering analysis integrated with the system architecture model using FMI standards. A workflow is provided that provides the enabling methodological capabilities. It starts with a statement of need and ends with system requirement verification. Detailed traceability is established that glues system engineering and engineering analysis together. Besides, a method is proposed for predicting the system’s complexity by calculating the complexity index that can be used to assess the complexity of the existing system and guide the design and development of a new system. To test and demonstrate this framework, a case study consisting of a complex district cooling system is implemented. The case study shows the framework’s capabilities in enabling the successful modeling of a complex district cooling system. The system architecture model was developed using SysML and the engineering analysis model using Modelica. The proposed framework supports system requirements verification activity. The analysis results show that the district chiller model developed using Modelica produces chilled water below 6.6 degrees Celsius, which satisfies the system requirement for the district chiller system captured in the SysML tool. Similarly, many such requirement verification capabilities using dynamic simulation integration with the high-level model provides the ability to perform continuous analysis and simulation during the system development process. The systems architecture complexity index is measured for the district cooling case study from the black-box and white box-perspective. The measured complexity index showed that the system architecture’s behavioral aspect increases exponentially compared to the structural aspect. The systems architecture’s complexity index at black-box and white-box was 4.998 and 67.3927, respectively.</div>
20

Lämplighetsundersökning av olika system för att producera kyla : Fallstudie för en fastighet med bageri, restaurang och kontor

Östlin, Robert January 2020 (has links)
Kyla produceras med ett antal helt skilda metoder. Denna rapport och fallstudie tar hänsyn till fyra metoder för kylning, kompressordriven-, absorptions-, fri-, och fjärrkyla. En del i problematiken är att systemen har mycket olika tekniska utformningar och krav på fastigheten, så som geografi och närhet till stora tekniska system som fjärrvärme och fjärrkyla. Kylsystemen jämfördes för att finna vilket kylsystem som var lämpligast samt vilket som hade den mest gynnsamma taxeringen för fastigheten. Kylsystemens lämplighet bedömdes framförallt efter underhållsbehov, men även storlek och ljudnivå. Fastigheten som utgör examensarbetets studieobjekt har ett kylbehov på 150 kW, vilket attribueras ett bageri, restaurang, kontor samt kylbänkar m.fl. Dessa har ett kylbehov under framförallt fyra sommarmånader, där kylbänkar m.fl även har ett kylbehov under resterande året. Flera studier har gjorts och pekar på att kylbehovet i framtiden kommer att öka, även om en exakt prognos inte kan ges. Det är även tydligt att alla de ovan nämnda kylsystemslösningarna har en roll att spela framöver. Examensarbetet har framförallt använt sig av en litteraturstudie för att besvara frågeställningarna. För litteraturstudien användes hemsidor som Discovery och ScienceDirect. För att beräkna energiförbrukning, drifttider och total kostnad så har Microsoft Excel använts. Framförallt för kylproduktion med kompressor, där det givna referensaggregatet har fyra olika driftfall beroende på kylbehov, varav ett är kylproduktion med frikyla. För att vikta frikylans andel har klimatdata från SMHI (2020) använts. Programmet har även använts för att sammanställa de tabeller och figurer som presenteras i resultatet. Prisförslag har givits efter personliga kommunikation per e-mail och telefonintervjuer med energiproducenter och tillverkare av kylaggregat. Resultatet visade att fjärrkyla var det för studieobjektet mest lönsamma alternativet, det står även för det system som är lämpligast då det är helt underhållsfritt för kunden. Anledningen till dess lönsamhet tillskrevs framförallt dess låga investeringskostnad. Att använda Gavleån för ren frikyla visade sig inte vara möjligt då temperaturen i ån är för hög sommartid. Även absorptionskyla visade sig vara olämpligt för studieobjektet då temperaturen i det lokala fjärrvärmenätet är för låg samtidigt som investeringskostnaden blivit hög. För absorptionskyla hade ett extra system behövts installeras, vilket rapporten inte kunnat prissätta. Rapporten visar däremot att metoden att producera kyla med absorptionsaggregat har potential att under rätt förutsättningar ersätta kompressorkyla. Detta för att minska dels belastningen på elnätet samt som ett sätt att minska CO2-utsläpp globalt, genom export av elektricitet till Europa. Detta arbete visar att dagens teknik är begränsad men att framtida teknik visar sig ha potential. Rapporten fann även att vidare arbete med vinning kunnat utföras för att identifiera absorptionskylas expansionspotential. / Cooling is produced with several completely differentiated methods. This report and case study considers four different methods of cooling, vapor-compression-, absorption-, free- and district cooling. A part of the problem is that the systems have vastly different technical configuration and requirement of a facility, such as geography and vicinity to other big technical system such as district cooling and district heating. The cooling systems are compared to find the method that is most suitable and has the most beneficial assessment. The different methods suitablitiy was graded based on, noise level, size and required maintenance. The facility that constitutes this thesis study has a cooling demand of 150kW, which is attributed to a bakery, a restaurant, an office and cooling benches etc. These have a cooling demand during four summer months, where cooling benches etc also have a demand during the rest of the year. Multiple studies showcase and point out that the cooling demand will grow in the future, even if a precise prognosis is not made. It is also clear that these above-mentioned cooling systems have a continuing role to play going forward. This thesis has foremostly used a literature review to answer the research questions. For the review webpages such as Discovery and ScienceDirect was used. To calculate the energy consumption, running hours and total yearly cost Microsoft Excel was used. Especially when cool produced with the compressor unit. The reference unit has four different operating modes depending on the cooling demand, one of the modes is production with free cooling. To value the share and impact that free cooling has, Microsoft Excel is used in combination with statistical data from SMHI (2020). Microsoft Excel is also used to compile the tables and figures in the “results” section. The pricing published in this report is based on personal communications per e-mail and phone interviews with energy producers and manufacturers of different cooling units. The result of the thesis show that district cooling is the most beneficial solution for cooling the facility. As well as the most suitable system since it is completely maintenance free for a customer. The reason for its profitability is attributed to its low investment cost. Using the nearby river for free cooling was deemed impossible because of its high temperature during the summers. Using absorption cooling was also considered unsuitable for the case object because of the low temperature in the local district heating network during summer times, as well as the high investment cost required because of it. To make absorption cooling suitable an additional system for cooling the processes would have to be installed, which this report has not been able to price.

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