Arlanda airport is Sweden’s largest airport. The demand for comfort cooling of the airport’s buildings is high and is mainly provided by district cooling. District cooling is based on the same principle as district heating. A centralized production facility for the district cooling offers advantages from both an environmental and operational perspective. Swedavia, which owns, operates and develops the airport, therefore advocates that district cooling always should be the first hand choice to meet the demand of comfort cooling. In the current situation the district cooling system at Arlanda is operated at its full capacity. This makes additional connections impossible. The purpose of this thesis has been to examine the possibilities of increasing the deliveries of comfort cooling through Arlanda Airport district cooling system. This report describes Arlanda airport’s district cooling system and its development prospects. District cooling requires a system perspective. It is important that all components in the system interact to achieve an optimized use of the distributed cold water. In addition this report also addresses the parameters that affect a building's cooling load and the measures that can reduce the power load, which is the main parameter that limits the number of users on the district cooling network.

Strävan att nå ett hållbart samhälle har varit en av de viktigaste aspekterna under 2000-talet. Det stora problemet är hur målet skall nås. Användningen av fossila bränslen måste minskas, men vilken energikälla skall ersätta dem? Biomassa har haft en viktig roll i minskningen av fossila bränslen som använts i uppvärmningssyfte. Teknikutveckling har medfört att dess betydelse kan bli än viktigare. Snabb pyrolys är en process där en bioolja, kallad pyrolysolja, produceras genom nedbrytning av biomassa. Denna process kräver extern värmetillförsel, vilket gör den lämplig att integrera i ett kraftvärmeverk. Problemet med kraftvärmeverk är dess minimala drift under sommarhalvåret. En pyrolysintegration skulle öka användandet av anläggningen. Pyrolysoljan som utvinns kan ersätta fossila bränslen som används i pannor och turbiner. Den kan även uppgraderas till bio-diesel men det är i dagsläget inte lönsamt. Pyrolysintegration skulle få maximal produktion under sommarhalvåret. Under denna period ökar också behovet av kyla. Under sommaren täcks en del av kylbehovet av kylkompressorer som drivs på elektricitet. Ett hållbart samhälle innebär att rätt form av energi utnyttjas. Att använda den högvärdiga energiformen elektricitet till komfort är inte hållbart. Absorptionskylcykeln är en kylmaskin som är snarlik en kylkompressor, med den stora skillnaden att den drivs på lågtempererad värme. För att utvinna pyrolysoljan från pyrolysprocessen krävs det en eller flera kondensorer. Kondenseringsvärmen kan användas för att driva en absorptionskylmaskin. Förenklat omvandlar den värme till kyla med minimalt behov av elektricitet. Pyrolysintegreringen med fjärrkyleproduktion skulle producera värme, elektricitet, pyrolysolja och fjärrkyla, allt med ursprung från biomassa. Potentialen i denna anläggning är stor, vilket resultatet av denna undersökning visar. Ett kraftvärmeverk med en förbränningspanna på 80 MW ångeffekt har studerats och tre olika fall undersöktes. Det första fallet maximerar pyrolysoljeproduktionen och producerar 78 000 ton pyrolysolja/år och fjärrkyla motsvarande 11 GWh. Det andra fallet maximerar fjärrkyleproduktionen och producerar 37 GWh fjärrkyla och pyrolysolja motsvarande 68 000 ton/år. Det sista fallet ger en mer balanserad produktion på 74 000 ton pyrolysolja/år och 22 GWh fjärrkyla. Framtida forskning bör undersöka hur kyleffekten varierar under dygnet i ett försök att ytterligare effektivisera anläggningen. Kondenseringsbeteendet hos pyrolysolja utvunnen från biomassa med ursprung från Skandinavien bör också undersökas vidare. / The pursuit of a sustainable society has been one of the most important aspects in the 21st century. The big problem is how to achieve this goal. The use of fossil fuels must be reduced, but which energy source should be used to replace it? Biomass has played a significant role in the reduction of fossil fuels used for heating purposes. With new technology its importance may be even greater. Fast pyrolysis is a process where a bio oil, called pyrolysis oil, is produced by the degradation of biomass. This process requires external heat, which makes it suitable to integrate with a combined heat and power plant. The problem of combined heat and power plants are its minimal operational during the summer. A pyrolysis integration would increase the use of the facility. The pyrolysis oil that is extracted can replace fossil fuels used in boilers and turbines. It can also be upgraded to bio-diesel, but currently that process is too costly. The pyrolysis integration would get maximum production during the summer months. During the same period the cooling demand is increased. During the summer cooling load is covered largely of refrigerating compressors run on electricity. A sustainable society means that the right kind of energy is utilized. Using the high-quality form of energy electricity for comfort is not sustainable. The absorption refrigeration cycle is a chiller similar to a refrigeration compressor, with the major difference that it runs on low-temperature water. The pyrolysis process requires one or more condensers in order to extract pyrolysis oil. When the pyrolysis oil condenses low temperature heat is produced. This condensation heat can be used to drive an absorption chiller, which simplified converts heat to cold, with minimal need for electricity. The pyrolysis integration with district cooling production would produce heat, electricity, pyrolysis oil and cooling, all originating from biomass. The result from the study shows potential. A cogeneration plant with a combustion boiler steam output of 80 MW has been studied and three different cases were investigated. The first case maximizes the production of pyrolysis oil and produces 78 000 tonnes of pyrolysis oil / year and district cooling equivalent to 11 GWh. The second case maximizes the district cooling production and produces 37 GWh of district cooling and pyrolysis oil equivalent to 68 000 tonnes / year. The last study provides a more balanced production of 74 000 tons of pyrolysis oil / year and 22 GWh of district cooling. Future studies should investigate how the cooling effect varies during the day in an attempt to further improve the efficiency of the plant. The liquefaction behavior of pyrolysis oil derived from biomass originating from Scandinavia should also be investigated further.

Vattenfall Heat AB is a district heat provider in Drefviken, but has yet to establish any cooling systems in this area. This thesis examines the potential client base within the area today and over the coming 20 years. The feasibility of the most common cooling technologies is evaluated and results show a total potential for an installed capacity of 30 MW providing 50 GWh of cooling per year. One of the examined areas shows good prospect for heat driven absorption chillers during the summer months when the heat load is limited.

No description available.

Efterfrågan av kyla ökar i Sverige trots det kalla klimatet vilket då medför att behovet av fjärrkyla kan öka. Fjärrkyla är en centraliserad kylproduktion med fördelar som säkrare drift, minskade haverier samt att buller avlägsnas i jämförelse med lokala kylanläggningar. Således är absorptionskyla ett alternativ till fjärrkyla som börjar bli mer och mer intressant för fjärrvärmeintegrering. Syftet med rapporten är att ge företaget Öresundskraft ett underlag över de tekniska och ekonomiska förutsättningarna för absorptionskyla i Helsingborg. Problemställningarna har varit att undersöka: temperaturen på fjärrvärmen som ska användas till absorptionsanläggningen, hur absorptionsmaskinens kylfaktor påverkar förutsättningarna, hur absorptionsanläggningen ska dimensioneras, utreda olika placeringsalternativ för absorptionsanläggningen, om den befintliga ackumulatortanken kan användas i framtiden och om det är lönsamt att investera i en absorptionsanläggning. Problemställningarna besvarades genom intervjuer, sammanställning och beräkning av data, granskning av forskningslitteratur samt annan litteratur. Slutsatser som författarna har kommit fram till är att absorptionsmaskinen ska dimensioneras till 2,2 MW och att den ska placeras på Västhamnsverket. Under de förutsättningar att det fanns tillgång till billig värme samt att driften endast sker på sommaren fick resultatet ett utfall som gav lönsamhet i en absorptionsanläggning. / The cooling demand increases in Sweden despite the cold climate, which could cause the increase of district cooling. District cooling is a centralized cooling system with multiple benefits such as safer operations, reduced failures and removal of rumbling that will otherwise occur in local cooling systems. That’s why the absorption chiller is becoming more and more interesting to incorporate indistrict heating.The purpose of this report is to give the company Öresundskraft the technical and economic conditions for absorption cooling in Helsingborg. The main goal with the report have been to investigate: which temperature from the district heating system will be used for the absorptions chiller, how the coefficient of performance affects the conditions of absorption chiller, different dimensions for absorption chiller, different placement options for absorption chiller, if the existing cool water storage tank can be used in the future, is it profitable to invest in an absorption plant. The main goal questions have been answered through interviews, compilation and calculation of data, examination of research literature and other literature. Conclusions the authors were able to find is that the absorption chiller should be sized to 2,2 MW and it should be placed on Västhamnsverket. Under the conditions that there was access to cheap heat and only operating during the summer the result to invest in an absorption plant was profitable.

Under sommarmånaderna är behovet i fjärrvärmenät lågt, vilket innebär att fjärrvärmeproducenter i större utsträckning kan elda de mest lönsamma bränslena för att täcka behovet. Vid Linköpings kraftvärmeverk eldas under sommarperioden stora mängder billigt avfall vilket leder till låga och ibland negativa marginalkostnader i produktionen. Därmed är det intressant att utnyttja denna värme i så stor mån som möjligt, vilket kan göras via fjärrvärmedrivna absorptionskylmaskiner. Absorptionskylmaskiner används i dagsläget för produktion av fjärrkyla i Linköping, men är dessutom möjliga att använda för isproduktion.Denna rapport är tänkt att agera underlag för de beslut som fastighetsbolaget Lejonfastigheter AB i Linköping tar angående framtiden för kylsystemet vid Linköpings ishall. Rapporten syftar till att utreda möjligheterna för att installera en absorptionskylmaskin för isproduktion till ispistarna vid området Stångebro i Linköping. Som komplettering till den befintliga maskinparken bestående av eldrivna kompressorkylmaskiner skulle en absorptionskylmaskin kunna leda till en minskad elförbrukning i isproduktionen.Utöver detta syftar rapporten även till att undersöka effektiviseringsåtgärder för de befintliga kompressorkylmaskinerna, i form av en sänkning av kondenseringstemperaturen. Temperatursänkningen, som innebär att hela kompressorcykeln blir effektivare och att kompressorernas elförbrukning sänks, uppnås genom att använda fjärrkyla i kylningen av kondensorerna. Resultaten visar att den undersökta absorptionskylmaskinen inte leder till några kostnadsminskningar, utan är lika dyr eller dyrare än de befintliga kompressorkylmaskinerna under större delen av året. Däremot visar sig ett byte av kondensorkylning för de befintliga kompressorkylmaskinerna från dagens kylning mot utomhusluft till kylning med fjärrkyla, kunna ge en årlig besparing på runt 350 000 kr. Denna siffra inkluderar även ett byte av komfortkyla från dagens system med kompressorkylmaskin, till att istället använda sig av fjärrkyla direkt. Dessutom kan en sänkning av den årliga abonnerade toppeffekten för den inköpta elektriciteten erhållas i och med kylmaskinernas ökade effektivitet. Inkluderat investeringskostnader, så som rörläggning, fås en ungefärlig återbetalningstid på 13 år. Arbetet i denna rapport innehåller ett antal uppskattningar och osäkerheter vilket gör att det verkliga fallet kan komma att skilja sig från de resultat som här presenteras. Det är därmed intressant för framtiden att i mera detalj studera hur en eventuell absorptionskylmaskin skulle passa in i systemet med kompressorkylmaskiner, samt hur fjärrkylenätet på bästa sätt integreras i arenaområdets energisystem.

Denna studie undersöker absorptionstekniken i syfte att ta reda på förutsättningarna för absorptionskyla i Härnösand. En investeringskalkyl har genomförts för att bedöma lönsamheten. I huvudsak har en litteraturstudie genomförts och för investeringskalkylen har nuvärdesmetoden använts samt att produktspecifikationer har efterfrågats från de största leverantörerna i världen. Resultatet visar att det finns två typer av kommersialiserade absorptionskylmaskiner på marknaden, varav den ena är tillämpbar för decentraliserad kylproduktion i fjärrvärmenät vid temperaturer kring 75 °C, och den andra för högre temperaturer kring 120-150 °C och lämpar sig därmed inte för decentraliserad kylproduktion. Det forskas och utvecklas kring andra mer avancerade tekniker och investeringskalkylen visar att en investering är lönsam beroende på storleken på absorptionskylmaskinen och försäljningspriset på kylan som levereras till kunden. Slutsatsen är att säljargument och en motivering måste tas fram varför kunden ska välja att få sin kyla levererad via en absorptionskylmaskin istället för en kompressorkylmaskin. / This study examines the absorption cooling technology in order to find the prerequisites of absorption cooling in Härnösand. An investment appraisal has been completed to ensure profitability. Mainly, a literature review has been conducted and the net present value decision rule has been used for the investment appraisal and product specifications have been requested from the main global suppliers. The result shows that there are essentially two absorption chillers commercialized in the market, one of which is applicable for decentralized cooling production in a district heating network at temperatures around 75 °C, and the second which is applicable for temperatures in the range of 120-150 °C and thus not suitable for decentralized cooling production. Research and development for more advanced techniques is ongoing and the investment appraisal shows that the profitability is depending on the size of the chiller unit and the selling price for the cooling energy. The conclusion is that a sale proposal and a motivation are needed on why the customer should choose to have their cooling delivered from an absorption chiller instead of a compressor chiller.

<p>E.ON Värme in Örebro produces electricity and delivers heat and cooling to customers in the region. The Åby Plant operates as a combined heat and power (CHP) plant and runs mostly on different biofuels. A new boiler and turbine is projected for the plant and will start operating fully during year 2012. This creates new possibilities for the existing small scale district cooling production. The number of cooling subscribers is today low and the power output is approximately 7.7 MW but has a great potential of growing in the future. Higher electricity prices, due to the deregulated electricity market and growing environmental concerns motivate the use of district cooling. Cooling production at E.ON Värme in Örebro today comes from modified heat pumps with low efficiency and free cooling. The idea is to replace the heat pumps with either new compression cooling machines, absorption cooling machines (ACM) or a mixture of both. This thesis analyzes possible benefits with the use of heat driven cooling i.e. absorption cooling compared with conventional compression cooling.</p><p>Excess heat from electricity generation in CHP plants is often a problem during the warm period of the year. Normally most of the heat is distributed to industries and households for heating. However, during the summer, the demand for district heating is low which constrain electricity production. The absorption technique utilizes heat as fuel and increases electricity generation during warm periods. This together with a decrease in electricity consumption has positive effects on the environment since it reduces electricity produced in plants controlling margin production. Those plants are most often coal condense plants with high emissions of fossil CO2.</p><p>Most scientists believe that CO2 emissions from human activities are the main cause to the increasing greenhouse effect. The importance of reducing CO2 emissions is therefore high and is one of the motives for district cooling based on ACM that replaces small local electricity driven chillers. Since the Åby plant uses mostly biofuels the contribution of fossil CO2 is low.</p><p>ACM utilizes heat as fuel, therefore the positive effects related to ACM are fairly obvious when the electricity price and the demand for cooling are high. To analyze and optimize the energy system in Örebro, a model was created in the program MODEST, which is software developed at Linköping Institute of Technology. Optimizations with different cooling demands and electricity prices have been made. The cooling production mix is split up in two scenarios, a visionary scenario where no restrictions are considered and a restricted scenario with restricted ACM capacity. The results have been gathered and analyzed and supports the common statements about absorption cooling.</p><p>A simulation of the visionary scenario with unrestricted ACM capacity together with the highest cooling demand (20 MW) and the highest electricity prices (European prices), gave an annual decrease in global CO2 emissions of 9 400 tonnes compared to a scenario with only compression cooling machines. Furthermore, the system running cost was almost 9 MSEK lower on an annual basis. In the restricted scenario, a pay-off analysis shows that the additional costs due to ACM is covered by the lower system cost in less than 3 years when the electricity prices are as forecasted for 2012-2015. All the simulations where absorption cooling was a part of the energy system gave positive results both from an economical and environmental point of view.</p>

E.ON Värme in Örebro produces electricity and delivers heat and cooling to customers in the region. The Åby Plant operates as a combined heat and power (CHP) plant and runs mostly on different biofuels. A new boiler and turbine is projected for the plant and will start operating fully during year 2012. This creates new possibilities for the existing small scale district cooling production. The number of cooling subscribers is today low and the power output is approximately 7.7 MW but has a great potential of growing in the future. Higher electricity prices, due to the deregulated electricity market and growing environmental concerns motivate the use of district cooling. Cooling production at E.ON Värme in Örebro today comes from modified heat pumps with low efficiency and free cooling. The idea is to replace the heat pumps with either new compression cooling machines, absorption cooling machines (ACM) or a mixture of both. This thesis analyzes possible benefits with the use of heat driven cooling i.e. absorption cooling compared with conventional compression cooling. Excess heat from electricity generation in CHP plants is often a problem during the warm period of the year. Normally most of the heat is distributed to industries and households for heating. However, during the summer, the demand for district heating is low which constrain electricity production. The absorption technique utilizes heat as fuel and increases electricity generation during warm periods. This together with a decrease in electricity consumption has positive effects on the environment since it reduces electricity produced in plants controlling margin production. Those plants are most often coal condense plants with high emissions of fossil CO2. Most scientists believe that CO2 emissions from human activities are the main cause to the increasing greenhouse effect. The importance of reducing CO2 emissions is therefore high and is one of the motives for district cooling based on ACM that replaces small local electricity driven chillers. Since the Åby plant uses mostly biofuels the contribution of fossil CO2 is low. ACM utilizes heat as fuel, therefore the positive effects related to ACM are fairly obvious when the electricity price and the demand for cooling are high. To analyze and optimize the energy system in Örebro, a model was created in the program MODEST, which is software developed at Linköping Institute of Technology. Optimizations with different cooling demands and electricity prices have been made. The cooling production mix is split up in two scenarios, a visionary scenario where no restrictions are considered and a restricted scenario with restricted ACM capacity. The results have been gathered and analyzed and supports the common statements about absorption cooling. A simulation of the visionary scenario with unrestricted ACM capacity together with the highest cooling demand (20 MW) and the highest electricity prices (European prices), gave an annual decrease in global CO2 emissions of 9 400 tonnes compared to a scenario with only compression cooling machines. Furthermore, the system running cost was almost 9 MSEK lower on an annual basis. In the restricted scenario, a pay-off analysis shows that the additional costs due to ACM is covered by the lower system cost in less than 3 years when the electricity prices are as forecasted for 2012-2015. All the simulations where absorption cooling was a part of the energy system gave positive results both from an economical and environmental point of view.

The real estate company Ihus is facing an expansion of its comfort cooling in Noatun,Uppsala, to provide the buildings in the block with cooling. The buildings in Noatunare mainly used for office premises, where the requirements for an accepted indoorclimate is great. However, it’s uncertain whether Ihus should continue, as currently,producing comfort cooling by themselves using a compressor chiller, or if they shouldconnect themselves to Vattenfall’s district cooling net. The purpose of this report is to examine which technique of cooling is best suited forIhus and their buildings in Noatun. It should also work as a guideline for othercompanies facing the same problem as Ihus. In addition, the result should give an ideaof how cooling by using compressor chillers compares to district cooling in aneconomical perspective, aswell as in an environmental and performance perspective. This report is based mainly on studies of literature covering cooling, approximationsof contractor costs with the help of the calculation tool Wikells Sektionsdata andassays of life cycle costs for different refrigeration alternatives. The result is showing that refrigeration by using compressor chillers seems to be themost advantageous option for the buildings in Noatun. Investments of a newcompressor chiller and associated components to cover the cooling demand in theblock appears to be a better option than district cooling.The costs of district cooling varies greatly depending on its origin and geographicallocation. Because of these great variations, it’s difficult to come to a conclusion onwhat type of comfort cooling is the least expensive in all situations. Every uniquesituation requires an investigation.In order to determine the impact on the environment for each type of comfortcooling a more thoroughly analysis is required. However, district cooling is likely tobe a better option regarding the environmental impact due to a centralizedpreparation of the refrigerants. A centralized preparation allows easier environmentalefficiency work since it’s easier to oversee emissions in one large facility than in manysmaller ones. The performance of different types of comfort cooling has shown to be too difficultto compare in this report. The reason for this is mainly because of limited access ofinformation regarding performance, but also because district cooling and cooling byusing compressor chillers differs greatly technically. Therefore, it’s difficult to conducta fair comparison of their performance.