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.

Master of Science / Department of Architectural Engineering and Construction Science / Fred L. Hasler / This paper discusses the advantages of applying a utility centralized chilled water system as the district cooling choice for facilities in the high-density urban areas of China and how it will influence China’s development in the next decades. Presently, the Chinese government is trying to contribute to the world’s energy-saving goals as well as determine its sustainable development framework. As air pollution has become one of the main problems in China, indoor air quality (IAQ) is likely to gain priority as a building design consideration in the future. Consistent with this fact, this paper proposes an optimum HVAC system for cooling purposes to the Chinese government. Compared to unitary HVAC systems, the centralized HVAC system has significant advantages in system efficiency, energy reduction and cost savings and can, therefore, be a better choice. Furthermore, the paper will focus on the centralized chilled water system and demonstrate why they better match the development model in China. The application of the system in high-density urban areas will also be discussed. Due to a lack of understanding that the energy consumption of unitary systems, the first comparison presented is between unitary HVAC systems and centralized HVAC systems in individual buildings. The comparison presented will focus on the energy-saving benefits of the centralized HVAC system in individual buildings and its contribution to sustainable development. Consequently, prescribing a centralized chilled water system as a utility district cooling system and applying a centralized chilled water system to each individual building in the highdensity urban areas will be compared. Cost savings, including initial cost and life cycle cost, are the metrics used in this comparison. Additionally, energy consumption and system reliability will be explored in determining which model will be more appropriate for China's development. The paper concludes that the centralized chilled water system should become the mainstream in the high-density urban area in China. Several recommendations are also made to the Chinese government on setting up utility centralized chilled water systems.

This master’s thesis has been performed in Bangkok, Thailand at the company Eco Design Consultant Co., Ltd. The aim is to investigate the possibilities to generate absorption cooling from municipal solid waste in the Bangkok area. The investigation includes a comparison between waste incineration and biogas production with combustion to see which alternative is preferable. During the investigation, a Swedish perspective has been used. The research for the report mainly consisted of published scientific articles from acknowledged sources as well as information from different Thai authorities. Also, experts within different areas were contacted and interviewed. In order to determine which of the two techniques (waste incineration or biogas production with combustion) that is best suited to generate absorption cooling, a model was designed. This model involved several parameters regarding e.g. plant efficiency, amount of treated waste and internal heat usage. As for the results of the model, three parameters were calculated: the generated cooling, the net electricity generation and the reduced greenhouse emissions. The overall Thai municipal solid waste generation in Thailand is estimated to approximately 15 million tons per year and the majority of the waste ends up at open dumps or landfills. There are only two to three waste incinerators in the country and a few projects with biogas generation from municipal solid waste. The main electricity is today generated from natural gas which makes the majority of the Thai electricity production fossil fuel based. As for absorption cooling, two applications of this technique has been found in Thailand during the research; one at the Naresuan University and one at the Suvarnabhumi airport in Bangkok. The model resulted in that the best alternative to power absorption cooling technique is waste incineration. This alternative has potential to generate 3200 GWh cooling per year and 1100 GWh electricity per year. Also, this alternative resulted in the largest decrease of greenhouse gas emissions, ‐500 000 tons per year. The model also showed that the same amounts of generated cooling and electricity can never be achieved from biogas production with combustion compared to waste incineration. Regardless, waste incineration has an important drawback: the citizens of Thailand seem to oppose further development of waste incineration in the country. The biogas technique seems more approved in Thailand, which benefits this alternative. Due to the high moisture and organic content in the municipal solid waste, a combination between the two waste handling alternatives is suggested. This way, the most energy can be withdrawn from the waste and the volume of disposed waste is minimized. Our overall conclusion is that the absorption cooling technique has great potential in Thailand. There is an increasing power‐ and cooling demand, absorption cooling generated from either or both of the alternatives can satisfy these demands while reducing greenhouse gas emissions. We also believes that the cost for using absorption cooling has to be lower than for the current compression cooling if the new technique is to be implemented further.

District Cooling Systems (DCS) have been widely applied in large institutions such as universities, government facilities, commercial districts, airports, etc. The hydraulic system of a large DCS can be complicated. They often stem from an original design that has had extensive additions and deletions over time. Expanding or retrofitting such a system involves large capital investment. Consideration of future expansion is often required. Therefore, a thorough study of the whole system at the planning phase is crucial. An effective hydraulic model for the existing DCS will become a powerful analysis tool for this purpose. Engineers can use the model to explore alternative system configurations to find an optimal way of accommodating the DCS hydraulic system to the planned future unit. This thesis presents the first complete procedure for the use of commercial simulation software to construct the hydraulic model for a large District Cooling System (DCS). A model for one of the largest DCS hydraulic systems in the United States has been developed based on this procedure and has been successfully utilized to assist its master planning study.

<p>The energy consumption is continuous to increase around the world and with that follows the demand for sustainable solutions for future energy systems. With growing energy consumption from fossil based fuels the threat of global warming through release of CO₂ to the atmosphere increases. The demand for cooling is also growing which would result in an increased consumption of electricity if the cooling demand was to be fulfilled by electrically driven cooling technology. A more sustainable solution can be to use heat-driven absorption cooling where waste heat may be used as driving energy instead of electricity.</p><p>This thesis focuses on the role and potential of absorption cooling in future energy systems. Two types of energy systems are investigated: a district energy system based on waste incineration and a distributed energy system with natural gas as fuel. In both cases, low temperature waste heat is used as driving energy for the absorption cooling. The main focus is to evaluate the absorption technology in an environmental perspective, in terms of reduced CO₂ emissions. Economic evaluations are also performed. The reduced electricity when using absorption cooling instead of compression cooling is quantified and expressed as an increased net electrical yield.</p><p>The results show that absorption cooling is an environmentally friendly way to produce cooling as it reduces the use of electrically driven cooling in the energy system and therefore also reduces global CO₂ emissions. In the small-scale trigeneration system the electricity use is lowered with 84 % as compared to cooling production with compression chillers only. The CO₂ emissions can be lowered to 45 CO₂/MWhc by using recoverable waste heat as driving heat for absorption chillers. However, the most cost effective cooling solution in a district energy system is a combination between absorption and compression cooling technologies according to the study.</p><p>Absorption chillers have the potential to be suitable bottoming cycles for power production in distributed systems. Net electrical yields over 55 % may be reached in some cases with gas motors and absorption chillers. This small-scale system for cogeneration of power and cooling shows electrical efficiencies comparable to large-scale power plants and may contribute to reducing peak electricity demand associated with the cooling demand.</p>

<p>I did my presentation through Centra infron of Professor Bjorn Palm and Dr. Sad Jarall.</p>

The energy consumption is continuous to increase around the world and with that follows the demand for sustainable solutions for future energy systems. With growing energy consumption from fossil based fuels the threat of global warming through release of CO2 to the atmosphere increases. The demand for cooling is also growing which would result in an increased consumption of electricity if the cooling demand was to be fulfilled by electrically driven cooling technology. A more sustainable solution can be to use heat-driven absorption cooling where waste heat may be used as driving energy instead of electricity. This thesis focuses on the role and potential of absorption cooling in future energy systems. Two types of energy systems are investigated: a district energy system based on waste incineration and a distributed energy system with natural gas as fuel. In both cases, low temperature waste heat is used as driving energy for the absorption cooling. The main focus is to evaluate the absorption technology in an environmental perspective, in terms of reduced CO2 emissions. Economic evaluations are also performed. The reduced electricity when using absorption cooling instead of compression cooling is quantified and expressed as an increased net electrical yield. The results show that absorption cooling is an environmentally friendly way to produce cooling as it reduces the use of electrically driven cooling in the energy system and therefore also reduces global CO2 emissions. In the small-scale trigeneration system the electricity use is lowered with 84 % as compared to cooling production with compression chillers only. The CO2 emissions can be lowered to 45 CO2/MWhc by using recoverable waste heat as driving heat for absorption chillers. However, the most cost effective cooling solution in a district energy system is a combination between absorption and compression cooling technologies according to the study. Absorption chillers have the potential to be suitable bottoming cycles for power production in distributed systems. Net electrical yields over 55 % may be reached in some cases with gas motors and absorption chillers. This small-scale system for cogeneration of power and cooling shows electrical efficiencies comparable to large-scale power plants and may contribute to reducing peak electricity demand associated with the cooling demand. / QC 20101209

Demand for cooling has been increasing around the world for the last couple of decades due to various reasons, and it will continue to increase in the future particularly in developing countries. Traditionally, cooling demand is met by decentralised electrically driven appliances which affect energy, economy and environment as well. District Cooling Plant (DCP) is an innovative alternative means of providing comfort cooling. DCP is becoming an essential infrastructure in modern city development owning to many benefits compared to decentralized cooling technology. Demand Response Management (DRM) is largely applied for Demand Side management of electrical grid. Demand of electrical energy is closely connected with the demand of alternative form of energy such as heating, cooling and mechanical energy. Therefore, application of DR concept should be applied beyond the electrical grid; in particular, it could be applied to any interconnected district energy systems. District Cooling Plant is one of a potential candidate and Demand Response management solutions can be applied to DCP for sustainable operation. The study of demand response and its applicability has not been attempted previously for district cooling systems. To our knowledge, this is the first attempt to evaluate its applicability and economical feasibility. This thesis focused on some of the DR objectives which have the potential to implement for DCP of a mixed-use city. General published data on mixed use city developments and a specific city in Dubai was taken as a case study to show the usefulness on DRM objectives. This study primarily addressed the issues related to load management. The findings are: DRM creates greater flexibility in demand management without compromising service levels. Also it reduces the operation cost and impact to environment. However implementation is a big challenge. Therefore implementation strategies are also proposed as a part of recommendation which includes a generic model for demand response management. Moreover, a review is provided on key enabling technologies that are needed for effective demand response management. Finally this thesis concludes with recommendations for prospective applications and potential future works.

Kylbehovet i fastigheter spås öka i framtiden till följd av en ökad användning av elektroniskutrustning, ökade krav på inomhuskomfort samt en global uppvärmning som enligt forskarekommer att höja medeltemperaturen på jorden. För att möta efterfrågan på kyla genomför BorlängeEnergi tillsammans med teknikkonsultfirman INTEC utredningar om etablering av fjärrkyla iBorlänge.För att etableringen av ett fjärrkylnät ska vara aktuellt krävs att affären blir lönsam för BorlängeEnergi samtidigt som de potentiella kunderna ser erbjudandet som attraktivt. Syftet med studien äratt i samarbete med INTEC och Borlänge Energi göra ett beräkningsprogram i kalkylprogrammetExcel som kan ge underlag för beslutsfattande kring utformningen av ett fjärrkylnät i Framtidsdaleni Borlänge. För att påvisa beräkningsprogrammets användbarhet har lönsamhetsberäkningar och enkänslighetsanalys genomförts på ett förslag till etablering av fjärrkylnätet som tagits fram avuppdragsgivare.Studien utfördes genom att bearbeta litteratur om funktionen för ett fjärrkylnät samt metoder förinvesteringskalkylering. Detta gjordes genom att söka relevant information på databaser samtrekommendationer och riktlinjer från myndigheter. Även annan väsentlig litteratur i bokformanvändes. Beräkningsprogrammet utvecklades i kalkylprogrammet Excel och beräkningar gjordesbaserat på givna förutsättningar.Siffrorna i studien ska inte ses som slutgiltiga och bör betraktas som en indikator för om det finnsanledning att gå vidare med en djupare utredning. Resultaten visar att det nätt och jämnt finnsekonomisk lönsamhet för Borlänge Energi i en investering i ett småskaligt fjärrkylnät utan att tahänsyn till mjuka parametrar i kalkylen. För kunderna blir det mer ekonomiskt lönsamt över enlängre tidshorisont att ansluta sig till fjärrkyla i jämförelse med att investera i en enskild kylcentral.Resultaten förutsätter dock att driftskostnaden för absorptionskylmaskinen hålls låg och är beroendeav en större anslutningsavgift från en av kunderna. Driftskostnaden för absorptionskylmaskinen ären osäkerhetsfaktor då produktionskostnaden i framtiden kan komma att höjas på grund av enminskad tillgång till industriell restvärme. / The cooling demand is projected to grow in the future due to an increase in use of electrical equipment, increased requirements regarding indoor comfort as well as global warming, which according to scientists will raise the average air temperature on earth. To meet the cooling demand, Borlänge Energi, together with the technology consulting firm INTEC, is conducting investigations into the establishment of district cooling in Borlänge.For the establishment of a district cooling network to be relevant, it is required that the deal becomes profitable for Borlänge Energi at the same time as the potential customers see the offer as attractive. The purpose of the study is to, in collaboration with INTEC and Borlänge Energi, make a calculation program in Excel which can provide a basis for decision-making regarding the design of a district cooling network in Framtidsdalen in Borlänge. To demonstrate the usefulness of the calculation program, profitability calculations and a sensitivity analysis have been carried out on a proposal for the expansion of the district cooling network developed by INTEC.The study was carried out by processing literature on the function of a district cooling network and methods for investment calculation. This was done by searching for relevant information in databases as well as recommendations and guidelines from authorities. Other essential books on the given topic were also used. Profitability calculations were performed using the developed calculation tool in Excel and were based on given assumptions.Although the figures in the study should not be seen as definitive and should be regarded as an indicator of whether there is reason to proceed with a deeper investigation, the results show that there is only just economic profitability for Borlänge Energi to invest in a small-scale district cooling network without taking consideration of soft parameters. For customers, it will be more economically profitable over a longer time horizon to join district cooling in comparison with investing in an individual cooling system. The results assume, however, that the operating cost of the absorption cooling machine is kept low and is dependent on a larger connection fee from one of the customers. The operating cost of the absorption cooling machine is an uncertainty factor as the production cost may increase in the future due to a reduced supply of industrial waste heat.

5th generation district heating and cooling is a novel approach to district heating and cooling networks. Instead of a centralized energy supply, the technology relies on multiple building-level energy centers, equipped with heat pumps and chillers. The energy centers are connected to a low-temperature district energy network which allows for energy exchange by rejecting the waste heat and coolth produced by the chillers and heat pumps. A growing interest in 5th generation district heating and cooling has spurred new research on the topic but there are still many unanswered questions regarding the viability of the concept, both from a technical and economical perspective. This thesis aims to increase the understanding of these types of networks by creating a simple model that can be used to evaluate the performance of a potential 5th generation district heating and cooling network, based primarily on the hourly heating and cooling demand of different building types. The model was implemented on 2 theoretical building clusters located in Bristol, UK. Cluster 1 was made up of offices, retail establishments, and hotels while cluster 2 consisted of residential buildings, hospitals, and data centers. The network was modelled after a 2-pipe closed loop system. Cluster 2 was able to limit the ratio of external heat and coolth addition to the system to 30% while cluster 1 required 53%. The low-temperature network enabled the connected heat pumps to reach a seasonal coefficient of performance of 3.4 for both clusters. The cooling equipment (free cooling heat exchanger and chiller) managed to reach a seasonal coefficient of performance of 17 in the case of cluster 1 and 18.2 for cluster 2. Distribution losses in the network amounted to about 3.2% for the warm pipe while the cold pipe gained 1.4% of coolth from the ambient. The results of the simulations indicate that the seasonality of the heating and cooling demand is one of the main factors to account for when designing a 5th generation district heating and cooling network. Highly seasonal heating and cooling demands lead to less possibilities for energy exchange on the network and will thus require more energy addition or increased energy storage capacity. The findings of this thesis seem to suggest that the advantages of 5th generation district heating and cooling networks are highly dependent on the demand profile of the connected buildings. Future research should aim to establish under what conditions these networks are economically viable. This will depend on several factors but arguably the most important ones are the amount of energy required to balance the network, cost of decentralized substations, and availability of cheap low-temperature heat and seasonal storage.