The electricity system is particularly susceptible to climate change due to the close interconnectedness between not only electricity production and consumption to climate, but also the interdependence of many European countries in terms of electricity imports and exports. This study provides a country based relative analysis of a number of selected European countries’ electricity system vulnerability to climate change. Taking into account a number of quantitative influencing factors, the vulnerability of each country is examined both for the current system and using some projected data. Ultimately the result of the analysis is a relative ranked vulnerability index based on a number of qualitative indicators. Overall, countries that either cannot currently meet their own electricity consumption demand with inland production (Luxembourg), or countries that experience and will experience the warmest national mean temperatures, and are expected to see increases in their summer electricity consumption are found to be the most vulnerable for example Greece and Italy. Countries such as the Czech Republic, France and Norway that consistently export surplus electricity and will experience decreases in winter electricity consumption peaks were found to be the least vulnerable to climate change. The inclusion of some qualitative factors however may subject their future vulnerability to increase. The findings of this study enable countries to identify the main factors that increase their electricity system vulnerability and proceed with adaptation measures that are the most eective in decreasing vulnerability.

This thesis focuses on using photovoltaic produced electricity to power air conditioners in a tropical climate. The study takes place in Surabaya, Indonesia at two different locations the classroom, located at the UBAYA campus and the home office, 10 km away. Indonesia has an average solar irradiation of about 4.8 kWh/m²/day (PWC Indonesia, 2013) which is for ideal conditions for these tests. At the home office, tests were conducted on different photovoltaic systems. A series of measuring devices recorded the performance of the 800 W PV system and the consumption of the 1.35 kW air conditioner (cooling capacity). To have an off grid system many of the components need to be oversized. The inverter has to be oversized to meet the startup load of the air conditioner, which can be 3 to 8 times the operating power (Rozenblat, 2013). High energy consumption of the air conditioner would require a large battery storage to provide one day of autonomy. The PV systems output must at least match the consumption of the air conditioner. A grid connect system provides a much better solution with the 800 W PV system providing 80 % of the 3.5 kWh load of the air conditioner, the other 20 % coming from the grid during periods of low irradiation. In this system the startup load is provided by the grid so the inverter does not need to be oversized. With the grid-connected system, the PV panel’s production does not need to match the consumption of the air conditioner, although a smaller PV array will mean a smaller percentage of the load will be covered by PV. Using the results from the home office tests and results from measurements made in the classroom. Two different PV systems (8 kW and 12 kW) were simulated to power both the current air conditioners (COP 2.78) and new air conditioners (COP 4.0). The payback period of the systems can vary greatly depending on if a feed in tariff is awarded or not. If the feed in tariff is awarded the best system is the 12 kW system, with a payback period of 4.3 years and a levelized cost of energy at -3,334 IDR/kWh. If the feed in tariff is not granted then the 8 kW system is the best choice with a lower payback period and lower levelized cost of energy than the 12 kW system under the same conditions.

[pt] O setor de refrigeração tem um papel fundamental e crescente na vida moderna. Seus usos vão desde processos industriais até conservação de alimentos passando por aplicações de conforto térmico. Tamanho peso econômico também se reflete nas emissões de poluentes do segmento. Acordos internacionais têm sido implementados com o objetivo de substituir fluidos refrigerantes que são danosos à camada de ozônio ou com alto potencial de aquecimento global. Outras abordagens visam reduzir o nível de emissões por meio da diminuição do consumo energético da operação de sistemas de refrigeração. Nesse sentido, este trabalho investiga a implementação de uma estratégia baseada em controle preditivo para sistemas de expansão direta. O objetivo foi verificar se o controlador baseado nessa abordagem seria capaz de controlar a temperatura interna de um ambiente. Os resultados mostram que o controlador proposto foi eficaz nessa tarefa para o caso de temperaturas externas constantes, porém ineficaz em contexto dinâmico. Quando o desempenho dessa abordagem foi comparado àquele de um mesmo sistema operando com controlador de duas velocidades, os resultados foram inferiores. A estratégia de controle preditivo foi capaz de manter a temperatura do ambiente refrigerado dentro da faixa desejada em 53 por cento do tempo contra 96 por cento do esquema de duas velocidades. Em paralelo, estudou-se também a aplicação do método de estimação estados em horizonte móvel. O objetivo foi discutir se era possível inferir parâmetros do ciclo de refrigeração sem efetivamente mensurá-los. Os resultados mostram que o modelo de refrigeração proposto é observável em condições externas constantes. Além disso, uma comparação de desempenho entre o sistema operando com fluidos diferentes foi realizada. O intuito foi mostrar as possibilidades do método de estimação no que tange o cálculo de indicadores de desempenho. / [en] The refrigeration sector has a fundamental and growing role in modern life. Its uses range from industrial processes and food preservation to applications of thermal comfort. Its economic weight size is reflected in the level of pollutant emissions of the segment. International agreements have been implemented with the objective of replacing refrigerant fluids that are harmful to the ozone layer or with a high global warming potential. These initiatives seek to mitigate the direct impact of the release of gases into the atmosphere. Other approaches aim to reduce the level of emissions by reducing the energy consumption of the operation of these systems.In this sense, this work investigates the implementation of a strategy based on predictive control for direct expansion systems. The objective was to verify if the control strategy based on this approach would be able to keep the internal temperature of an room within a defined range. The results show that the proposed control scheme was effective for the case of constant external temperatures, but ineffective in a dynamic context. Comparing the performance of this approach to the same system operating with a two velocities control scheme, the results were inferior. The predictive control strategy was able to keep the temperature within the desired range in 53 per cent of the simulation time versus 96 per cent of the two velocity aproach. In parallel, the application of the estimation method states in moving horizon was also studied. The objective was to discuss whether it was possible to infer parameters of the refrigeration cycle without actually measuring them. The results show that the refrigeration model proposed is observable under constant external conditions. In addition, a performance comparison between the system operating with different fluids was performed. The goal was to show the possibilities of this estimation method with respect to the calculation of performance metrics.

The mobile cooling and climate control industry provides a range of diverse solutions concerning the maintenance of temperature for comfortable living and safe transportation of goods over long distances. One of the major focuses of the industry is the transport sector for which products like cooling boxes and mobile air conditioners are exclusively designed for commercial and leisure purposes. However, the associated emissions released due to their use and the impact they have in the wake of the global climate crisis has led the industry to initiate activities and set targets to address this issue. This study aims to draw sustainable strategy recommendations to the mobile cooling and climate control industry by conducting a Life Cycle Assessment (LCA) of four products and a materiality assessment for a company manufacturing cooling boxes and mobile air conditioners, therefore accelerating the industry’s transition towards sustainability. The objectives are to identify potential material and process-related environmental hotspots over the life cycle of the products and carry out a materiality assessment that identifies topics of materiality for the company, this to outline strategies based on the results of both the LCA and the materiality assessment to improve the company’s sustainability in its operations. The results of the LCA highlighted the role of the use phase as one of the main contributors to the environmental impact from the use of cooling boxes and mobile air conditioners, while the manufacturing of the products and the end-of-life phase are shown to contribute also to the overall impact. Furthermore, different sensitivity scenarios revealed the potential that different materials, the use of batteries and the implementation of a take-back system have to decrease the environmental impacts of the products. From the materiality assessment fourteen material topics were identified to have significance and priority to the company. Based on these results, a total of nine strategies addressing the sustainability of the company and its products were outlined. Across the assessment, three key focus aspects were observed which can facilitate the sustainability transition of the company and industry: energy both in products and operations, collaboration with stakeholders, and circular economy principles and product innovation. Efforts within these areas can potentially improve the industry’s ability to tackle pressures from climate change and the increasing future demand. This study also exemplifies the potential benefits of a synergy between LCA and materiality assessment. It was observed that aiding the materiality assessment with the LCA results provides more tangibility to the results and decreases the subjectivity from the assessment in order to set future sustainability targets. / Mobilkylnings- och klimatkontrollsindustrin erbjuder många lösningar till temperaturhållning för bekvämt boende och säker transport av gods. Ett viktigt fokus för industrin är transportsektorn där produkter som kylboxar och mobil luftkonditionering specialkonstruerad för kommersiell och rekreationell användning. Växthusgasutsläppen från produkterna under användning har mot bakgrund av den globala klimatkrisen fått industrin att sätta mål och starta ett arbete för att minska utsläppen. Den här studien avser att ge hållbara strategier och rekommendationer till mobilkylnings- och klimatkontrollsindustrin genom att genomföra livscykelanalys (LCA) av fyra produkter och en materialanalys till ett företag som tillverkar kylboxar och mobila luftkonditioneringar för att driva industrins övergång till hållbarhet. Målen är att identifiera material- och processrelaterade miljöbelastningar över hela livscykeln av produkterna och genomföra en materialitetstsanalys för att identifiera materialitetsämnen. Utifrån LCA och materialitetsanalysen går att göra strategier att förbättra företagets hållbarhetsarbete. Resultat från LCAn visade vikten av användningsfasen som stod för den största miljöpåverkan från kylboxar or mobil luftkonditionering. Tillverkning och end-of-life hade också påverkan. Känslighetsanalyser visade också den potential materialval, batterianvändning och retursystem har att minska miljöpåverkan från produkter. Fjorton materialitetsämnen utpekades från materialitetsanalysen som viktiga för företaget. Dessa hanteras genom nio strategier som togs fram. Genom analys var tre övergripande fokusområden identifierade som kan underlätta företagets och industris hållbarhetsövergång. De är: energianvändning i både produkterna och företagets arbete, samarbeten med stakeholders samt cirkulär ekonomi och produktinnovation. Ansträngningar inom dessa områden kam förbättra industris förmåga att tackla trycket från klimatkrisen och ökad framtida efterfrågan. Studien visar också på synergin mellan LCA och materialitetsanalys. Att använda resultat från LCA i materialitetsanalysen gav tydligare resultat och minskar subjektiviteten vilket ger bättre förutsättningar när hållbarhetsmål ska sättas.

Enhanced Finned-Tube Condenser Design and Optimization Susan W. Stewart 173 pages Directed by Dr. Sam V. Shelton Finned-tube heat exchangers are widely used in space conditioning systems, as well as any other application requiring heat exchange between liquids and gases. Their most widespread use is in residential air conditioning systems. Residential systems dictate peak demand on the U.S. national grid, which occurs on the hot summer afternoons, and thereby sets the expensive infrastructure requirement of the nations power plant and electrical distribution system. In addition to peak demand, residential air conditioners are major energy users that dominate residential electrical costs and environmental impact. The only significant opportunity for electrical power use reduction of residential air conditioners is in technology improvement of the finned-tube heat exchangers, i.e., condenser and evaporator coils. With the oncoming redesign of these systems in the next five years to comply with the regulatory elimination of R-22 used in residential air conditioners today, improvement in the design technology of these systems is timely. An air conditioner condenser finned-tube coil design optimization methodology is derived and shown to lead to improved residential air conditioner efficiency at fixed equipment cost. This nonlinear optimization of the 14 required design parameters is impractical by systematic experimental testing and iteration of tens of thousands condenser coils in an air conditioning system. The developed methodology and results can be used in the redesign of residential systems for the new mandated environmentally friendly refrigerants and to meet increasing regulatory minimum system efficiencies. Additionally, plain fins and augmented fins, (louvered), are compared using the developed model and optimization scheme to show the effect of the augmentation on system performance. Furthermore, an isolated condenser model was developed using condenser entropy generation minimization as the figure of merit to minimize the model complexity and computation time. Isolated model optimizations are compared with the system model optimum designs.

Demand Side Management (DSM) is a term coined to describe the control of demand to optimize energy usage in a way beneficial to both users and utilities. There are different technologies and policies designed for DSM, and one of them is Direct Load Control (DLC) which refers to a utility directly controlling demand. In this thesis, an analysis of DLC for air conditioning units during summer in the Indian state of Karnataka is carried out. A new control mechanism is proposed, based on the local generation capacity, which seems to reduce until the monsoon season arrives, as the lack of rain reduces water levels in hydro power plants. The direct load control of ACs using this mechanism allows for 0.88% energy savings in a state where only around 5% of all households seem to have AC units and electricity is available for only 37% of the population. The mentioned savings could have significant economic impacts for both users and utilities, reduce the fossil-based energy consumption and/or improve issues such as blackouts and the lack of capacity to cover peak loads. Continuous improvements in both energy access and the economic conditions of the state will lead to a larger number of AC’s installed, meaning that a mechanism that reduces AC consumption could be of great utility for all stakeholders of the electricity sector. / Styrning av Efterfrågan (från Demand Side Management, DSM) är ett begrepp som myntats för att beskriva konsumtionskontroll för att optimera energianvändning på ett sätt som är fördelaktigt för både användare och samhällsservice. Det finns olika tekniker och taktiker utformade för DSM, och en av dem är Direkt Belastningskontroll (från Direct Load Control, DLC), vilket är ett verktyg för att direkt kontrollera efterfrågan. I denna avhandling genomförs en analys av DLC för luftkonditioneringsenheter under sommaren i den indiska delstaten Karnataka. En ny kontrollmekanism föreslås baserat på den lokala produktionskapaciteten, som verkar minska fram tills monsunsäsongen, eftersom bristen på regn minskar vattennivån i vattenkraftverk. Den direkta belastningskontrollen hos luftkonditioneringsenheter med denna mekanism möjliggör en energibesparing på 0,88% i ett stadium där endast cirka 5% av alla hushåll tycks ha luftkonditionering och elektricitet är tillgängligt för endast 37% av befolkningen. De nämnda besparingarna kan ha betydande ekonomiska effekter för både användare och samhällsservice, minska den fossilbaserade energiförbrukningen och/eller förbättra problem som strömavbrott och brist på kapacitet för att täcka toppbelastningar. Ständiga förbättringar av både energitillgång och de ekonomiska förhållandena i staten kommer att leda till att ett större antal luftkonditioneringsenheter installeras, vilket innebär att en mekanism som minskar konsumtionen hos luftkonditioneringsenheterna kan vara till stor nytta för alla intressenter i elsektorn.

[pt] O objetivo principal desta dissertação é o de buscar formas de modelar e controlar, adequadamente, condicionadores de ar de janela, pois tratam-se de máquinas que possuem um elevado consumo de energia, perdendo somente para o chuveiro elétrico. A contribuição do mesmo para a demanda do setor doméstico é da ordem de 7 %. As pesquisas de posse de eletrodomésticos mostram que somente 6 % dos domicílios têm instalada tal tipo de máquina, o que representa um expressivo potencial de crescimento para os próximos anos na aquisição deste produto. É oportuno observar que em edifí­cios comerciais, 48 % da energia é consumida com refrigeração, o que implica na necessidade de novos projetos em que centrais de grande porte sejam implantadas, visando um gasto comparativamente menor ao somatório de aparelhos individuais. / [en] This work involves the modeling of window air conditioners, with the purpose to obtain the electrical potential consume by itself, related to the medium external temperature. To obtain such goal, it was necessary the study of all features which involve their several components, aiming the conduct fitted from the parts, due to the result expected. It was made a public research with the users from these equipments. From this result, it was developed a stochastic model to be used in energy demand from a specific region, considering that the equipment / machine in use shows similar qualifications. After that, it was added to the system of machine a direct load control, which delay the compressor, obtaining an efficient working from it (saving demand), without affecting deeply normal using conditions. Finally, comparing two examples mentioned above, it was concluded that in the less powerful equipment (air conditioner) the thermal control with changed features, had good results, while more powerful equipments are more economic with direct load control. / [es] Esta disertación tiene como objetivo principal buscar formas de modelar y controlar adecuadamente, equipos de aire acondicionado de tipo ventana, por tratarse de equipos que poseen un alto consumo de energía, superado tan solo por la ducha eléctrica. La contribución de éste para la demanda del sector doméstico es del orden de 7 %. Las investigaciones sobre la pose de electrodomésticos muestran que sólo el 6 % de los domicilios tiene instalada tal tipo de máquina, lo que representa um expresivo potencial de crescimiento en la adquisición de este producto para los próximos años. Es oportuno observar que en edificios comerciales, 48 % de la energia consumida se refiere a refrigeración, lo que nos lleva a la necesidad de nuevos proyectos donde, centrales de grande porte seam implantadas, para conseguir un gasto comparativamente menor a la suma de equipos individuales.

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2017-02-08T14:37:06Z No. of bitstreams: 1 Henrique Zenker dos Santos_.pdf: 9480964 bytes, checksum: 5a3a14f9704ce1135e84db57590283a7 (MD5) / Made available in DSpace on 2017-02-08T14:37:06Z (GMT). No. of bitstreams: 1 Henrique Zenker dos Santos_.pdf: 9480964 bytes, checksum: 5a3a14f9704ce1135e84db57590283a7 (MD5) Previous issue date: 2016-10-21 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Países desenvolvidos apresentam crescimento contínuo nas taxas globais de consumo de energia. Um dos fatores preponderantes está relacionado ao uso de condicionadores de ar para manutenção das condições de conforto no interior de edificações, onde tal parcela já atinge valores de consumo superiores aos dos setores de indústria e transporte. Sabe-se que o consumo devido ao condicionamento de ar afeta diretamente o desempenho energético e ambiental de uma edificação e, por conseguinte, a qualidade de habitação e de vida dos usuários. No Brasil este processo ocasiona um vertiginoso incremento nos gastos públicos, com inúmeras consequências de ordem econômica e social. Dados do Ministério de Minas e Energia indicam que 20% da energia consumida no país é destinada ao abastecimento de residências. Cenário este que tende a evoluir devido aos constantes lançamentos do mercado imobiliário, derivativos de planos habitacionais estimulados pelo governo federal (como o Minha Casa Minha Vida), em decorrência do déficit habitacional registrado no país. Atrelado a isso observa-se o baixo padrão construtivo das edificações e o emprego de materiais e esquadrias de qualidade igualmente diminutas, que acarretam em ineficiências de carga térmica. A taxa de infiltração em uma edificação é regida pela relação estabelecida por uma equação de lei de potência, caracterizada pela presença de um coeficiente de escoamento “C” e um expoente de escoamento “n” (geralmente da ordem de 0,667 [-]). Esta dissertação apresenta, para uma esquadria de alumínio, modelo de correr, o coeficiente de escoamento C = 0,028 [dm³/s.m.Pan] e o expoente de escoamento “n” 0,552 [-]. Para uma esquadria de PVC, modelo integrado, o coeficiente de escoamento C = 0,022 [dm³/s.m.Pan] e o expoente de escoamento “n” 0,605 [-]. / Developed countries have continued growth in global energy consumption rates. One of the most important factors is related to the use of air conditioners to the comfort conditions inside buildings’ maintenance, which such a part already reaches consumption values higher than the industry and transportation sectors. It is known that consumption due to air conditioning directly affects the energy and environmental performance of a building and therefore the house’s quality and the people’s life. In Brazil, this process leads to a big increase in public spending, with many consequences of economic and social order. Information from the Ministry of Mines and Energy indicate that 20% of the energy consumed in the country is used for supplying homes. This scenario tends to evolve due to the constant housing market releases, derived from housing plans stimulated by the federal government (such as “Minha Casa Minha vida”), in consequence of the housing deficit registered in the country. Related to this, it is observed the low construction standards of buildings and the use of materials and frames of low quality that lead to thermal load inefficiencies. Engineers and architects spend a part of their activities in creating scenarios for evaluating the thermal load calculation and vulnerability due to the influence caused by air infiltration into the environment. The infiltration rate of a building is managed by the established relationship by a power law equation, which is characterized by a flow coefficient "C" and a flow exponent "n" (usually on the value of 0.667 [-]). This work shows for an aluminum window, sliding template, the flow coefficient C = 0.028 [dm³/s.m.Pan] and the flow exponent "n" 0.552 [-]. For PVC window, integrated model, the flow coefficient C = 0.022 [dm³/s.m.Pan] and the exponent flow "n" 0.605 [-].

<p>With rising temperatures, urbanization, population growth, improving economic wellbeing, decarbonization and electrification efforts, the demand for space cooling and heating equipment is continuously increasing around the world. To counteract the effect of rising demand for air conditioners and heat pumps on total energy consumption, peak electricity demand, and emissions, it is crucial to promote the development and market penetration of energy-efficient systems. Establishing minimum energy performance standards (MEPS), energy labeling and utility programs are some of the effective and tested methods for achieving this goal. The technical basis for these energy efficiency standards is a testing and rating procedure for estimating equipment seasonal performance from laboratory tests. Although the current rating procedures provide standardized metrics to compare different equipment performances, they fail to appropriately characterize the field representative performance of systems by not considering the effects of: 1) test unit embedded controls, thermostat, and realistic interactions with the building load and dynamics; 2) different climate zones and building types; and 3) and other integrated accessories for improving energy efficiency such as economizer for rooftop units (RTUs). Therefore, current approaches for performance ratings neither incentives the development and implementation of improved system and control designs nor consumers with a metric that represents the advanced systems' actual energy savings. To address this, a load-based testing methodology that enables dynamic performance evaluation of equipment with its integrated controls, thermostat, and other accessories was recently proposed. The test methodology is based on the concept of emulating the response of a representative building conditioned by the test unit in a test lab using a virtual building model. </p> <p>In this work, the proposed load-based testing methodology was further extended, evaluated, and validated for residential heat pumps to integrate it into next-generation energy efficiency testing and rating procedures and to serve as a tool for engineers to develop and validate improved control algorithms in a laboratory setting. Further, a load-based testing method for evaluating the dynamic performance of RTUs with integrated economizers was also developed and demonstrated.</p> <p>A load-based testing approach previously developed for residential cooling equipment is extended for heat pump heating-mode and demonstrated for a variable-speed system. The heat pump's typical dynamic behaviors are captured along with controller imperfections that aren't reflected in current testing approaches. Further, a comprehensive comparison was performed between the proposed load-based testing approach to the current steady-state testing approach in the U.S., AHRI 210/240, based on performance evaluation of three residential variable-speed heat pumps to understand the differences and their significance for the next-generation rating procedure. For cooling mode, steady-state testing estimates higher seasonal performance, but for heating mode, the steady-state testing approach estimates higher seasonal performance for warmer climates and is comparable for colder climates. The load-based testing methodology was validated by comparing the laboratory performance of a heat pump to that of a residential building in a controlled environment. The virtual building modeling approach for building loads and thermal dynamics effectively captured these characteristics of the house. The heat pump's cycling rate response with run-time fraction, which represents the unit's overall dynamic response, matched well between lab load-based tests and house tests. The test unit's COP difference for cooling and heating tests was within 3% between the two facilities, except for 9% in 95°F and 6% in 104°F cooling dry-coil test intervals. To evaluate the applicability of the developed load-based testing methodology as next-generation rating standards, its repeatability and reproducibility were assessed based on multiple heat pump round-robin tests conducted in two labs. Overall, reasonable to good repeatability was observed in load-based test results in both labs, however, poor reproducibility was observed except for one heat pump heating mode results. A root cause analysis of the observed differences along with recommendations for a next-generation rating approach are presented. This work aided in the development of a CSA (Canadian Standards Association) standard EXP07:19 and its subsequent revision for equipment rating based on load-based testing.</p> <p>The application of the load-based testing methodology as a tool for the development and evaluation of a residential heat pump controller design was demonstrated. Further, a load-based testing methodology was developed and demonstrated for the dynamic performance evaluation of RTUs with integrated economizers in a test laboratory setting. Recommendations for future work to further develop and improve the repeatability, reproducibility, and representativeness of the load-based testing and rating approach for residential and commercial air conditioners and heat pumps are summarized at the end of the dissertation. </p>