Dissertations / Theses: 'Chiller systems'

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Lilly, Dana Elizabeth. "Analysis and performance of gas-electric hybrid chiller systems." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/15996.

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Liu, Hubert H. "Analytsis and performance optimization of commercial chiller/cooling tower systems." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/15895.

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Weber, Eric Dean. "Modeling and general optimization of commercial building chiller/cooling tower systems." Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/16874.

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Liao, Xiaohong. "The development of an air-cooled absorption chiller concept and its integration in CHP systems." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/2176.

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Thesis (Ph. D.) -- University of Maryland, College Park, 2004.
Thesis research directed by: Mechanical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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Mirza-Tolouee, Changiz M., and n/a. "Experimental study of zeotropic refrigerant mixture HFC-407C as a replacement for HCFC-22 in refrigeration and air-conditioning systems." Swinburne University of Technology, 2006. http://adt.lib.swin.edu.au./public/adt-VSWT20070416.141307.

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HCFC-22 is the world�s most widely used refrigerant. It serves in both residential and commercial applications, from small window units to large water chillers, and everything in between. Its particular combination of efficiency, capacity and pressure has made it a popular choice for equipment designers. Nevertheless, it does have some ODP, so international law set forth in the Montreal Protocol and its Copenhagen and Vienna amendments have put HCFC-22 on a phase out schedule. In developed countries, production of HCFC-22 will end no later than the year 2030. Zeotropic blend HFC-407C has been established as a drop-in alternative for HCFC-22 in the industry due to their zero Ozone Depletion Potential (ODP) and similarities in thermodynamic properties and performance. However, when a system is charged with a zeotropic mixture, it raises concerns about temperature glide at two-phase state, differential oil solubility and internal composition shift. Not enough research has been done to cover all aspects of alternative refrigerants applications in the systems. This research intended to explore behavior of this alternative refrigerants compare to HCFC-22 and challenges facing the industry in design, operation service and maintenance of these equipments. The purpose of this research is to investigate behavior of R407C refrigerant in chiller systems. This includes performance and efficiency variations when it replaces R22 in an existing system as well as challenges involved maintaining the system charged with R407C. It is a common practice in the industry these days to evacuate and completely recharge when part of the new refrigerant blend was leaked from the system. This has proved to be extremely costly exercise with grave environmental ramifications. This research is intended to address challenges faced in the real world and practical terms. Theoretical and experimental approaches used as a methodology in this work. The system mathematically modeled to predict detailed system performance and effect of the leak at various conditions. To make this feasible and accurate enough, two separate approaches made, first system performance for pure R22 and R407C, and second system subjected to range of leak fractions. The earlier model was relatively straight forward when compared to the latter. Modeling a system charged with R407C ternary mixture and subjected to range of leaks posed enormous challenges. A sophisticated experimental test apparatus was also designed and built. Comprehensive and detailed tests at various conditions were conducted with special attention on instrumental accuracy and correct methodology. The first part has been successfully modeled and predicted all the factors and performance with excellent accuracy when compared to the test results. In these approaches pure refrigerants R22 and R407C were used and simulated the system behavior at range of conditions. However, the second part was the most challenging ever. Comprehensive leak process simulations produced trends of R32/R125/R134a composition change as function of rate of leak. Starting from this point, equations have been created to represent the composition change as function of percentage of the leak. The system thermodynamic cycle was also modeled to calculate capacity, power input and COP at the range of the conditions. Despite many affecting parameters and complexity of the model, the mathematical model successfully predicted the test outcome with a very reasonable accuracy, averaging around 3% with some times reaching to 5 to 6%. On the experimental stage the system charged with the new HFC-407C was deliberately subjected to refrigerant leak at various leak stages. The aim was to objectively determine to what extend the gas leak can be still acceptable without going through the expensive complete gas charge. The effect of leak was tested and verified at 10% steps, from 10% up to 50% mass fraction for the total charge. It has been observed that at the leaks beyond 30%, the adverse effect on the capacity becomes more significant, from 8 to about 15% decrease. While the power input decreased at slower pace, from 3% up to about 8% depending on the test conditions. This translated to COP decrease ranging from 4 to about 7%. This capacity loss and efficiency decrease are significant figures which suggests that the system, here chiller, can not be allowed to degrade the performance to that extend and still continue operating.

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Ghaghazanian, Arash. "System Integration of PV/T Collectors in Solar Cooling Systems." Thesis, Högskolan Dalarna, Energiteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:du-19554.

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The demand for cooling and air-conditioning of building is increasingly ever growing. This increase is mostly due to population and economic growth in developing countries, and also desire for a higher quality of thermal comfort. Increase in the use of conventional cooling systems results in larger carbon footprint and more greenhouse gases considering their higher electricity consumption, and it occasionally creates peaks in electricity demand from power supply grid. Solar energy as a renewable energy source is an alternative to drive the cooling machines since the cooling load is generally high when solar radiation is high. This thesis examines the performance of PV/T solar collector manufactured by Solarus company in a solar cooling system for an office building in Dubai, New Delhi, Los Angeles and Cape Town. The study is carried out by analyzing climate data and the requirements for thermal comfort in office buildings. Cooling systems strongly depend on weather conditions and local climate. Cooling load of buildings depend on many parameters such as ambient temperature, indoor comfort temperature, solar gain to the building and internal gains including; number of occupant and electrical devices. The simulations were carried out by selecting a suitable thermally driven chiller and modeling it with PV/T solar collector in Polysun software. Fractional primary energy saving and solar fraction were introduced as key figures of the project to evaluate the performance of cooling system. Several parametric studies and simulations were determined according to PV/T aperture area and hot water storage tank volume. The fractional primary energy saving analysis revealed that thermally driven chillers, particularly adsorption chillers are not suitable to be utilizing in small size of solar cooling systems in hot and tropic climates such as Dubai and New Delhi. Adsorption chillers require more thermal energy to meet the cooling load in hot and dry climates. The adsorption chillers operate in their full capacity and in higher coefficient of performance when they run in a moderate climate since they can properly reject the exhaust heat. The simulation results also indicated that PV/T solar collector have higher efficiency in warmer climates, however it requires a larger size of PV/T collectors to supply the thermally driven chillers for providing cooling in hot climates. Therefore using an electrical chiller as backup gives much better results in terms of primary energy savings, since PV/T electrical production also can be used for backup electrical chiller in a net metering mechanism.

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Sala, Cardoso Enric. "Advanced energy management strategies for HVAC systems in smart buildings." Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/668528.

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The efficacy of the energy management systems at dealing with energy consumption in buildings has been a topic with a growing interest in recent years due to the ever-increasing global energy demand and the large percentage of energy being currently used by buildings. The scale of this sector has attracted research effort with the objective of uncovering potential improvement avenues and materializing them with the help of recent technological advances that could be exploited to lower the energetic footprint of buildings. Specifically, in the area of heating, ventilating and air conditioning installations, the availability of large amounts of historical data in building management software suites makes possible the study of how resource-efficient these systems really are when entrusted with ensuring occupant comfort. Actually, recent reports have shown that there is a gap between the ideal operating performance and the performance achieved in practice. Accordingly, this thesis considers the research of novel energy management strategies for heating, ventilating and air conditioning installations in buildings, aimed at narrowing the performance gap by employing data-driven methods to increase their context awareness, allowing management systems to steer the operation towards higher efficiency. This includes the advancement of modeling methodologies capable of extracting actionable knowledge from historical building behavior databases, through load forecasting and equipment operational performance estimation supporting the identification of a building’s context and energetic needs, and the development of a generalizable multi-objective optimization strategy aimed at meeting these needs while minimizing the consumption of energy. The experimental results obtained from the implementation of the developed methodologies show a significant potential for increasing energy efficiency of heating, ventilating and air conditioning systems while being sufficiently generic to support their usage in different installations having diverse equipment. In conclusion, a complete analysis and actuation framework was developed, implemented and validated by means of an experimental database acquired from a pilot plant during the research period of this thesis. The obtained results demonstrate the efficacy of the proposed standalone contributions, and as a whole represent a suitable solution for helping to increase the performance of heating, ventilating and air conditioning installations without affecting the comfort of their occupants.
L’eficàcia dels sistemes de gestió d’energia per afrontar el consum d’energia en edificis és un tema que ha rebut un interès en augment durant els darrers anys a causa de la creixent demanda global d’energia i del gran percentatge d’energia que n’utilitzen actualment els edificis. L’escala d’aquest sector ha atret l'atenció de nombrosa investigació amb l’objectiu de descobrir possibles vies de millora i materialitzar-les amb l’ajuda de recents avenços tecnològics que es podrien aprofitar per disminuir les necessitats energètiques dels edificis. Concretament, en l’àrea d’instal·lacions de calefacció, ventilació i climatització, la disponibilitat de grans bases de dades històriques als sistemes de gestió d’edificis fa possible l’estudi de com d'eficients són realment aquests sistemes quan s’encarreguen d'assegurar el confort dels seus ocupants. En realitat, informes recents indiquen que hi ha una diferència entre el rendiment operatiu ideal i el rendiment generalment assolit a la pràctica. En conseqüència, aquesta tesi considera la investigació de noves estratègies de gestió de l’energia per a instal·lacions de calefacció, ventilació i climatització en edificis, destinades a reduir la diferència de rendiment mitjançant l’ús de mètodes basats en dades per tal d'augmentar el seu coneixement contextual, permetent als sistemes de gestió dirigir l’operació cap a zones de treball amb un rendiment superior. Això inclou tant l’avanç de metodologies de modelat capaces d’extreure coneixement de bases de dades de comportaments històrics d’edificis a través de la previsió de càrregues de consum i l’estimació del rendiment operatiu dels equips que recolzin la identificació del context operatiu i de les necessitats energètiques d’un edifici, tant com del desenvolupament d’una estratègia d’optimització multi-objectiu generalitzable per tal de minimitzar el consum d’energia mentre es satisfan aquestes necessitats energètiques. Els resultats experimentals obtinguts a partir de la implementació de les metodologies desenvolupades mostren un potencial important per augmentar l'eficiència energètica dels sistemes de climatització, mentre que són prou genèrics com per permetre el seu ús en diferents instal·lacions i suportant equips diversos. En conclusió, durant aquesta tesi es va desenvolupar, implementar i validar un marc d’anàlisi i actuació complet mitjançant una base de dades experimental adquirida en una planta pilot durant el període d’investigació de la tesi. Els resultats obtinguts demostren l’eficàcia de les contribucions de manera individual i, en conjunt, representen una solució idònia per ajudar a augmentar el rendiment de les instal·lacions de climatització sense afectar el confort dels seus ocupants

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Richard, Scott J. "A Study on the Integration of a Novel Absorption Chiller into a Microscale Combined Cooling, Heating, and Power (Micro-CCHP) System." ScholarWorks@UNO, 2013. http://scholarworks.uno.edu/td/1765.

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This study explores the application of micro-CCHP systems that utilize a 30 kW gas microturbine and an absorption chiller. Engineering Equation Solver (EES) is used to model a novel single-effect and double-effect water-lithium bromide absorption chiller that integrates the heat recovery unit and cooling tower of a conventional CCHP system into the chiller’s design, reducing the cost and footprint of the system. The results of the EES model are used to perform heat and material balances for the micro-CCHP systems employing the novel integrated chillers, and energy budgets for these systems are developed. While the thermal performance of existing CCHP systems range from 50-70%, the resulting thermal performance of the new systems in this study can double those previously documented. The size of the new system can be significantly reduced to less than one third the size of the existing system.

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Le, Alex. "An economic comparison between two district cooling systems in Halmstad." Thesis, Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-25752.

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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.

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Hein, Maria. "The carbon footprint caused by the oversizing of building service systems : A case study of an NHS Hospital." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-281540.

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Energy usage in buildings is a main contributor to CO2 emissions and in order for the EU to reach the 2050 goal of carbon-neutrality, there is a great need to improve the energy efficiency in buildings, particularly commercial buildings that often are substantially overdesigned. Excess margins in the design process of building services result in an oversizing of these systems which has great environmental impacts, divided up as the operational and embodied carbon footprints. The heating and cooling system of an NHS Hospital in southern England was studied and modelled in order to identify whether the system was overdesigned and to quantify the oversizing’s carbon footprint, which was the aim of the study. The cooling system of the NHS Hospital was determined potentially oversized and the focus of the thesis was therefore on the cooling system. It included the chillers that provide cooling, and the associated adiabatic coolers that provide heat rejection, as well as the affiliated pumps. The carbon footprint of this system was quantified, based on the operational energy use, the current grid carbon factor, environmental performance evaluations of units, observations and assumptions, and its cooling capacity was compared to the demand of the hospital. An optimised alternative was developed through analysis of the current system and its capacity, and the demand at the site, as well as based on the learnings of the background research. The system was designed to consist of smaller chillers and a reduced pumping system, to more correctly match the cooling demand. The optimised system was also modelled, its capacity compared to the demand, and its carbon footprint quantified. A future estimation of the two systems’ carbon footprints was calculated for year 2035, based on a projected grid carbon factor. The systems’ setups and carbon footprints were then compared for the current and projected scenarios, and the results discussed, also in regard to mitigation strategies that could lead to a reduction of oversizing and lower the environmental impacts. The results indicate that the yearly carbon footprint difference for the current scenario was approximately 539 tonnes CO2 eq, which was 43% greater than the optimised system’s carbon footprint. Whereas the yearly difference for the projected scenario was estimated to approximately 562 tonnes CO2eq, which was 752% greater than the optimised system’s carbon footprint in a possible future. This demonstrates the great environmental impact caused by the oversizing of cooling systems. The current system’s embodied carbon footprint was estimated to 3.3% of the total carbon footprint for the current scenario, and 4.8% for the projected scenario. Whereas the optimised system’s embodied carbon footprint was estimated to 1.5% for the current scenario, and 8.6% for the projected scenario. This demonstrates the large share of the embodied carbon footprint of the current, oversized system, compared to the optimised system that is sized more correctly for the cooling demand. Furthermore, it shows the anticipated raised proportion of the embodied carbon footprint of a product or system’s total future carbon footprint, since it increases for both the systems with time. The elevated share of the embodied carbon footprint in the future raises the need to address this factor and make it a priority. The key to a correctly sized system that meets the demand was determined to be precise calculations of the requirements and the elimination of excess margins that lack quantifiable justification. This results in an improved environmental performance where the system operates at its optimum level. The stakeholders’ involvement and influence throughout a transparent design process with clear communication, and incentives that provide financial aid to appropriately sized systems, as well as environmental impact evaluations of products, among others, are essential factors with major influence on the outcome. These elements are considered crucial for the reduction of the excess carbon footprint caused by the oversizing of building service systems.
Byggnaders energianvändning är en markant bidragande faktor till koldioxidutsläppen, och för att EU ska kunna nå målet att vara klimatneutral år 2050 finns det ett stort behov av att förbättra energieffektiviteten i byggnader, särskilt kommersiella byggnader som ofta är väsentligt överdesignade. Överskottsmarginaler i designprocessen av byggnadstjänster resulterar i en överdimensionering, som har en enorm miljöpåverkan, vilken delas upp som det operativa och det inneslutna klimatavtrycket. Studiens syfte var att studera och modellera värme- och kylsystemet på ett sjukhus i södra England för att identifiera om systemet var överdimensionerat, och för att kvantifiera dess klimatavtryck. Sjukhusets kylsystem bedömdes vara potentiellt överdimensionerat och studiens fokus var därför på kylsystemet. Det inkluderade kylarna som ger kylning och de anknutna adiabatiska kylarna som ger värmebortförsel, samt de tillhörande pumparna. Klimatavtrycket för systemet kvantifierades, baserat på den operativa energianvändningen, den nuvarande koldioxidfaktorn för elnätet, miljöutvärderingar av enheter, observationer och antaganden, och dess kylkapacitet jämfördes med sjukhusets behov. Ett optimerat alternativ utvecklades genom analys av det nuvarande systemet och dess kapacitet, och behovet på platsen, samt baserat på lärdomarna i litteraturforskningen. Systemet var utformat för att bestå av mindre kylare och ett reducerat pumpsystem för att bättre matcha kylbehovet. Även det optimerade systemet modellerades, dess kapacitet jämfördes med behovet, och dess klimatavtryck kvantifierades. En framtida uppskattning av de två systemens klimatavtryck beräknades för år 2035, baserat på en prognostiserad koldioxidfaktor för elnätet. Systemens uppsättningar och klimatavtryck jämfördes för de nuvarande och framtida scenarierna, resultaten diskuterades sedan, även med avseende på mildringsstrategier som kan leda till en reducering av överdimensionering och minskad miljöpåverkan. Resultaten indikerar att den årliga skillnaden i klimatavtrycket för det nuvarande scenariot var cirka 539 ton koldioxidekvivalenter, vilket var 43% större än det optimerade systemets klimatavtryck. Medan den årliga skillnaden i klimatavtrycket för det framtida scenariot uppskattades till cirka 562 ton koldioxidekvivalenter, vilket var 752% större än det optimerade systemets klimatavtryck i en eventuell framtid. Detta visar på den stora miljöpåverkan som orsakas av överdimensionerade kylsystem. Det nuvarande systemets inneslutna klimatavtryck beräknades till 3.3% av det totala klimatavtrycket för det nuvarande scenariot, och 4.8% för det framtida scenariot. Medan det optimerade systemets inneslutna klimatavtryck för det nuvarande scenariot var 1.5%, och 8.6% för det framtida scenariot. Detta demonstrerar den stora andelen inneslutet klimatavtryck i det nuvarande systemet, jämfört med det optimerade systemet som är bättre anpassat för kylbehovet. Dessutom visar det som förväntat den ökade andelen inneslutet klimatavtryck för en produkts eller ett systems totala klimatavtryck i framtiden, eftersom båda systemens inneslutna klimatavtryck visade på en framtida ökning. Den framtida ökade andelen inneslutet klimatavtryck väcker behovet av att itu med denna växande faktor och göra den till en prioritering. Nyckeln till ett system med korrekt storlek, vars kapacitet möter behovet, bestämdes vara exakta beräkningar av kraven och frånvaron av överskottsmarginaler som saknar kvantifierbar motivering. Detta resulterar i en förbättrad miljöprestanda där systemet fungerar på sin optimala nivå. Berörda parters engagemang och inflytande genom en transparent designprocess med tydlig kommunikation, och incitament som ger ekonomiskt stöd till system av korrekt dimensionering, samt miljökonsekvensbedömningar av produkter, är några av de viktigaste faktorerna med stort inflytande på slutresultatet. Dessa element bedöms vara avgörande för att minska överskottet av klimatavtrycket som orsakas av en överdimensionering av byggnadstjänster.

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Saulich, Sven. "Generic design and investigation of solar cooling systems." Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/13627.

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This thesis presents work on a holistic approach for improving the overall design of solar cooling systems driven by solar thermal collectors. Newly developed methods for thermodynamic optimization of hydraulics and control were used to redesign an existing pilot plant. Measurements taken from the newly developed system show an 81% increase of the Solar Cooling Efficiency (SCEth) factor compared to the original pilot system. In addition to the improvements in system design, new efficiency factors for benchmarking solar cooling systems are presented. The Solar Supply Efficiency (SSEth) factor provides a means of quantifying the quality of solar thermal charging systems relative to the usable heat to drive the sorption process. The product of the SSEth with the already established COPth of the chiller, leads to the SCEth factor which, for the first time, provides a clear and concise benchmarking method for the overall design of solar cooling systems. Furthermore, the definition of a coefficient of performance, including irreversibilities from energy conversion (COPcon), enables a direct comparison of compression and sorption chiller technology. This new performance metric is applicable to all low-temperature heat-supply machines for direct comparison of different types or technologies. The achieved findings of this work led to an optimized generic design for solar cooling systems, which was successfully transferred to the market.

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Kang, Di. "Potential advantages of applying a centralized chilled water system to high-density urban areas in China." Kansas State University, 2017. http://hdl.handle.net/2097/35490.

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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.

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Robles, Sebastian. "Business intelligence in Chile, recommendations to develop local applications." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/70831.

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Thesis (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, June 2011.
"February 2010." Cataloged from PDF version of thesis.
Includes bibliographical references (p. 60).
The volume of information generated from enterprise applications is growing exponentially, and the cost of storage is decreasing rapidly. In addition, cloud-based applications, mobile devices and social networks are becoming relevant sources of unstructured data that provide essential information for strategic decisions making. Therefore, with time, enterprise databases will become more valuable for business but also much harder to integrate, process and analyze. Business Intelligence software was instrumental in helping organizations to analyze information and provide reports to support business decision-making. Accordingly, BI applications evolved as enterprise information grew, hardware-processing capacities developed, and storage cost is being reduced significantly. In this paper, we will analyze the current BI world market and compare it with the Chilean market, in order to come up with business plan recommendations for local developers and systems integrators interested in capitalizing the opportunities generated by the global BI software market consolidation.
by Sebastian Robles.
S.M.in Engineering and Management

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Klawunder, Shawn Eric. "Modeling and analysis of chilled water systems." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/16383.

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Tan, Yuk Wei. "Development of a small-scale absorption cooled water chiller." Thesis, Nottingham Trent University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324572.

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Sanfiorenzo, Amiel B. "Cooling system design tool for rapid development and analysis of chilled water systems aboard U.S. Navy surface ships." Thesis, Cambridge, Massachussetts, Massachussetts Institute of Technology, 2013. http://hdl.handle.net/10945/40254.

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CIVINS
Over the last several decades, there has been a dramatic increase in the complexity and power requirements of radars and other combat systems equipment aboard naval combatants and this trend is expected to continue for the foreseeable future. This increase in the power demand has a direct effect on the amount of heat which has to be removed by the cooling systems, with future combatants expected to require 5-10 times the cooling capacity currently installed on naval combatants (McGillan, Perotti, McCunney, & McGovern). In the past, the cooling system could be designed and integrated into the ship towards the later stages of the ship design process; however, this is no longer possible. The growing complexity and size of the cooling systems needed require preliminary design and integration in the early stages of the ship design process. To design and integrate cooling systems several tools are available to the naval architect, but vary in complexity and usefulness depending on the design stage considered. The focus of this thesis is on the early-stage design of cooling systems aboard U.S. Navy surface ships utilizing the principles of naval architecture and mechanical engineering concepts. The intent was to study the heat transfer process within the chilled water system and the auxiliary seawater system and develop a Cooling System Design Tool (CSDT) based on the thermodynamic laws that govern heat transfer as well as the hydrodynamic principles that govern fluid flow, specifically the incorporation of flow network analysis (FNA). The key purposes of the CSDT are to provide rapid visualization and analysis of the cooling system to test overall feasibility and performance of the system. The framework of the model was built using Matlab in conjunction with Excel. The program interacts with the user primarily through the command window, guiding the user through the design process. Some visualization is provided as the design progresses, allowing the user to quickly determine and correct errors in the design. The CSDT also displays important results of various analyses that can be performed on the data, including a weight summary, a static temperature distribution and a temperature distribution that captures transients in space and time. The program interaction, chilled water plots and analyses output enables the user with the ability to quickly visualize, develop and analyze cooling systems aboard naval vessels.

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Sanfiorenzo, Amiel B. (Amiel Benjamin). "Cooling system design tool for rapid development and analysis of chilled water systems aboard U.S. Navy surface ships." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/81588.

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Thesis (Nav. E. and S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.
Cataloged from PDF version of thesis. Vita.
Includes bibliographical references (p. 155-157).
Over the last several decades, there has been a dramatic increase in the complexity and power requirements of radars and other combat systems equipment aboard naval combatants and this trend is expected to continue for the foreseeable future. This increase in the power demand has a direct effect on the amount of heat which has to be removed by the cooling systems, with future combatants expected to require 5-10 times the cooling capacity currently installed on naval combatants (McGillan, Perotti, McCunney, & McGovern). In the past, the cooling system could be designed and integrated into the ship towards the later stages of the ship design process; however, this is no longer possible. The growing complexity and size of the cooling systems needed require preliminary design and integration in the early-stages of the ship design process. To design and integrate cooling systems several tools are available to the naval architect, but vary in complexity and usefulness depending on the design stage considered. The focus of this thesis is on the early-stage design of cooling systems aboard U.S. Navy surface ships utilizing the principles of naval architecture and mechanical engineering concepts. The intent was to study the heat transfer process within the chilled water system and the auxiliary seawater system and develop a Cooling System Design Tool (CSDT) based on the thermodynamic laws that govern heat transfer as well as the hydrodynamic principles that govern fluid flow, specifically the incorporation of flow network analysis (FNA). The key purposes of the CSDT are to provide rapid visualization and analysis of the cooling system to test overall feasibility and performance of the system. The framework of the model was built using Matlab in conjunction with Excel. The program interacts with the user primarily through the command window, guiding the user through the design process. Some visualization is provided as the design progresses, allowing the user to quickly determine and correct errors in the design. The CSDT also displays important results of various analyses that can be performed on the data, including a weight summary, a static temperature distribution, and a temperature distribution that captures transients in space and time. The program interaction, chilled water plots and analyses output enables the user with the ability to quickly visualize, develop and analyze cooling systems aboard naval vessels.
by Amiel B. Sanfiorenzo.
Nav.E.and S.M.

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18

Joyce, Charles Thane. "Optimized design of a commercial building chiller/cooking tower system." Thesis, Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/24115.

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19

Kalinga, Ranjith Shantha De Silva. "Adaptation of Solar Energy Driven Absorption Chillers for Air Conditioning in Commercial Building." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-23828.

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The most recent analysis of energy usage in the country reveled that nearly 50% of the power generation is used for air conditioning and mechanical ventilation most of which is used by commercial organizations. The grid generation mix that contains a high percentage of fossil fuel makes such energy usage environment unfriendly. Although absorption refrigeration is an old technique its economical application is limited to applications where cheap or waste heat energy is available despite decades of R&D, due to low COP, high initial cost and larger size. Heat input at Moderately high (over 120ᵒC) temperature and need to release large amount of heat to the environment through liquid or air cooling makes absorption chiller less conducive in cooling. Yet, being a tropical country, Sri Lanka has a better potential in adopting solar driven absorption refrigeration, if the chillers are operated at low temperature heat input that also promotes efficiency in storage that is mandatory due to fluctuation of energy source, subject to economic feasibility. The project aims designing and modeling of a solar power driven absorption chiller system that is adoptable to a selected medium size commercial organization. The proposed system uses heat energy around 100ᵒC and reusing fraction of energy expelled to the environment by suitably modifying operating parameter and thereby increasing efficiency of the system. Reduction of such heat losses and reducing heat input is achieved with the use of secondary heat exchange (brine) system that optimizes the energy usage. This arrangement will make efficient usage of solar heat storage, even in the considerable absence of solar power. System modeling and simulation of both basic double effect chiller and its modified versions were carried out and compared to evaluate improvement. The simulation of the modified system was used to obtain working parameters of the chiller so that a suitable solar collector, chilled water and heat rejection systems can be designed. Operational conditions of the cooling system are measured by the state sensors that feed inputs to the control system to achieve the optimum efficiency and their technical details are also included in the report.

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20

Zhang, Yanan. "System-Oriented Dynamic Modelling and Power Consumption Simulationfor an Industrial Chiller Plant." Thesis, KTH, Energiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-287725.

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Nowadays, the amount of energy consumed by Heating, Ventilation and Air Conditioning (HVAC) systemsposes threats to the improvement of global environment. Hence people have been dedicated to thedevelopment of energy-saving retrofit projects via optimized simulation in these chiller plants. However, recent research only focuses on the improvement of one or two devices instead of whole operating system,and researchers seldom pay attention to the comparison between different optimization strategies.As a result, by using Modelica/Dymola framework, a system-oriented dynamic model is constructed via theon-site investigation of an industrial chiller plant which located in Chengdu, China in this project. This system is composed of the individual control of multiple chillers, water pumps and cooling towers with a relative mean absolute error (RMAE) of 1.4% in the energy consumption simulation and hence can be regarded as a reliable model for further optimizations. After the implantation of two-months simulated data as system configuration, three optimization strategies including Baseline Strategy (BS), Sequence Optimization (SO) and Holistic Optimization (HO) within the full range cooling load ratio are investigated to explore the potentials of energy savings for this model. Among all three optimization approaches, HO strategy shows the outperforming reduction in energy consumption by 10.8% especially at low range of cooling load ratio. Moreover, based on HO method, two more advanced strategies which named as Holistic Optimization based on Cooling Load Time FrequencyAnalysis (HOTF) and Holistic Optimization based on Cooling Load Distribution Analysis (HOCL) are explored. The results turn out that both optimization strategies on this model can further decrease the energy consumption by 2.6% and 4.0% accordingly. In addition to this, HOTF also shows its own strength on low cost and operation simplicity.

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21

Moorehead, Lynnette Ann. "Design optimization of cooling tower systems for dual-stage absorption chillers." Thesis, Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/16360.

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22

Rees, Simon J. "Modelling of displacement ventilation and chilled ceiling systems using nodal models." Thesis, Loughborough University, 1998. https://dspace.lboro.ac.uk/2134/6880.

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Cooling and ventilation of office spaces by displacement ventilation and chilled ceiling panel systems is potentially more energy efficient than conventional air conditioning systems. Heat transfer in this type of system is characterised by the presence of vertical temperature gradients and significant radiant asymmetry. The room heat transfer models used in current building simulation methods do not allow adequate representation of this type of system due to their reliance on a single node to define the internal air temperature. The overall aim of the work described in the thesis has been to develop a model of this type of system that is suitable for use in annual building energy simulation. The model presented, is intermediate in complexity between a CFD numerical model and the current single air node models, having ten air nodes. The operating characteristics of displacement ventilation systems, used both with and without chilled ceiling panels, have been studied by making experimental measurements in a test chamber and by reference to published experimental data. Numerical calculations of the flow and temperature fields have been made with a coupled flow and radiant exchange CFD code. Steady state calculations have been made of displacement ventilation using a conjugate heat transfer method. Interesting oscillations in the flow and temperature field of displacement ventilation operating with a chilled ceiling have been found through adopting a fully transient calculation procedure. The thesis describes how the experimental and numerical data has been used to develop the structure and define the parameters of a simplified nodal model. The logical development of the model structure, from the most elementary model to one which is able to capture the effects of the temperature gradients and incomp1ete mixing of the air in the room is described. A method is also presented whereby the parameters of the model are found directly from the experimental data by solving the heat and mass balance equations of the nodal model. The parameters of the model have been generalised by analysing these calculations and by making use of established convection coefficient correlations. The performance of the model is demonstrated by firstly making comparisons of the experimental and numerical data under steady state conditions, and also by demonstrating that the model is able to reproduce the characteristics of displacement ventilation and chilled ceiling systems under different operating conditions.

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23

Graves, Rhett David. "Thermodynamic modeling and optimization of a screw compressor chiller and cooling tower system." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/427.

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This thesis presents a thermodynamic model for a screw chiller and cooling tower system for the purpose of developing an optimized control algorithm for the chiller plant. The thermodynamic chiller model is drawn from the thermodynamic models developed by Gordon and Ng (1996). However, the entropy production in the compressor is empirically related to the pressure difference measured across the compressor. The thermodynamic cooling tower model is the Baker & Shryock cooling tower model that is presented in ASHRAE Handbook - HVAC Systems and Equipment (1992). The models are coupled to form a chiller plant model which can be used to determine the optimal performance. Two correlations are then required to optimize the system: a wet-bulb/setpoint correlation and a fan speed/pump speed correlation. Using these correlations, a "quasi-optimal" operation can be achieved which will save 17% of the energy consumed by the chiller plant.

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24

Abadie, Brendan. "Power investment outlook for Chile to 2040." Thesis, KTH, Energi och klimatstudier, ECS, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-276819.

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This study aims to build a medium-term (2019-2040) model for the Chilean electricity generation system in the OSeMOSYS software, a linear cost optimisation model, in light of the most recent developments in government policy and targets. In 2019, the Chilean government committed to decommissioning all coal plants by 2040 at the latest, and set out a non-binding target to be carbon neutral by 2050. The carbon neutrality target could be enshrined in the climate change law, which has yet to be ratified. In this thesis, a focus was put on the upfront capital cost of the system, and the emissions attributable to Chile’s GHG Inventory (called the SNI GHG in Chile) from operating the system. Three scenarios are developed within the thesis, in line with three paths the power system may follow: a BAU scenario including current power purchase agreements, a scenario in which power purchase agreements for fossil fuels are bought out and the free market then takes over, and a non-conventional renewable energy (NCRE) scenario in which certain renewable technologies account for 68% of production in 2040. The model is validated against the results from 2019 and a broadly similar model developed in the private sector. Sensitivity analysis scenarios were conducted for the input parameters: price of natural gas, price of coal, capital cost of solar PV, capital cost of wind, capital cost of wind & solar, and the capacity factor of hydropower. The sensitivity analyses show the most sensitive input parameters are the price of natural gas and capital cost of wind with respect to the outputs of capital cost, NCRE production ratio such as the share of all solar, wind, and certain hydro technologies as a percentage of total electricity production and GHG emissions.
Denna studie syftar till att bygga en medelfristig (2019-2040) modell för det chilenska elproduktionssystemet i programvaran OSeMOSYS, en linjär kostnadsoptimeringsmodell, mot bakgrund av den senaste utvecklingen i regeringens politik och mål. År 2019 åtog sig den chilenska regeringen att stänga av alla kolanläggningar senast 2040 och fastställde ett icke-bindande mål att vara koldioxidneutralt år 2050. Målet om koldioxidneutralitet kan fastställas i lagen om klimatförändringar, som ännu inte har ratificeras. Detta arbete fokuserar på systemets kapitalkostnad i förväg och de utsläpp som kan hänföras till Chiles GHG-inventering, kallad SNI GHG i Chile, från drift av systemet. Tre scenarier utvecklas inom avhandlingen, i linje med tre scenarier som kraftsystemet kan följa: ett BAU-scenario inklusive nuvarande kraftköpsavtal, ett scenario där kraftköpsavtal för fossila bränslen köps ut och den fria marknaden sedan tar över, och ett scenario med icke-konventionell förnybar energi (NCRE) där vissa förnybara tekniker står för 68% av produktionen 2040. Modellen valideras mot resultaten från 2019 och en i stort sett liknande modell utvecklad i den privata sektorn. Känslighetsanalysscenarier genomfördes för ingångsparametrarna: pris på naturgas, kol på pris, kapitalkostnad för solceller, vindkraft, kapitalkostnad för vind & sol och kapacitetsfaktor för vattenkraft. Känslighetsanalyserna visar att de mest känsliga ingångsparametrarna är priset på naturgas och kapitalkostnad för vind med avseende på kapacitetskostnadens produktion, NCRE-produktionskvoten, till exempel andelen av alla sol-, vind- och vissa hydroteknologier i procent total elproduktion) och växthusgasutsläpp.

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25

Arena, Noemi. "Life cycle engineering of a system to deliver self-chilled beverages." Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/812336/.

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The chill-on-demand system is a technology designed to provide cooled products on demand, thereby avoiding any requirement for chilled storage. It uses the cooling effect provided by the endothermic desorption of carbon dioxide previously adsorbed onto a bed of activated carbon contained in an inner component of the self-chilling product. This has the potential to be applied to any type of product that needs to be cold at the point of consumption. The principles of life cycle engineering have been utilized to evaluate the overall environmental performance of one possible application of this technology: a self-chilling beverage can, with a steel outer can to contain the beverage and an inner aluminium can to contain the adsorbent. The primary aim of this research is to devise a way to ensure that the self-chilling can supplies the best cooling performance with minimal global environmental impact. First, the adsorption/desorption process as a means of cooling was investigated, together with its application to the specific case of carbon dioxide adsorbed on a bed of activated carbon obtained from coconut shells. A specific experimental activity was designed and supported by the implementation of a transient heat exchange model. Next, the potential environmental impacts of the product were evaluated by using a Life Cycle Assessment tool. The analysis considered all the life cycle stages of a self-chilling can: from the manufacture of each part of the beverage container, to its utilization and end-of-life management. The results, compared with those of a conventional beverage can, highlight the importance of using activated carbon derived from biomass and locating its production in countries with a low carbon-intensity electricity supply. More substantial environmental and technical improvements would depend on finding adsorbents with much larger capacity, and developing a system with very high rates of recovery and re-use.

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26

Harrell, Justin M. "Improving efficiency in the SIUC campus chilled water system using exergy analysis /." Available to subscribers only, 2008. http://proquest.umi.com/pqdweb?did=1559849671&sid=17&Fmt=2&clientId=1509&RQT=309&VName=PQD.

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Thesis (M.S.)--Southern Illinois University Carbondale, 2008.
"Department of Mechanical Engineering and Energy Processes." Includes bibliographical references (pages 122-124). Also available online.

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27

Cereceda, Francisco, Sharif Chacoff, Ignacio Montiglio, Giordana Saavedra, and Sergio Sariego. "Digital systems." Tesis, Universidad de Chile, 2009. http://www.repositorio.uchile.cl/handle/2250/111669.

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Tesis para optar al grado de Magíster en Administración (MBA)
No disponible a texto completo
La promulgación y entrada en vigencia en abril de 2009 de la Ley 20285 de transparencia y acceso a la información pública obliga a los órganos del Estado a disponer de herramientas y formas expeditas y rápidas, que atiendan y respondan los requerimientos que cualquier ciudadano u organización realice acerca de información que el organismo posea y administre. La aplicación de esta normativa encuentra a los órganos del Estado en una situación de precariedad estructural compleja de resolver en cuanto a la capacidad de responder a los requerimientos de información, sobre todo con aquella dimensión que se denomina Transparencia Pasiva y que se refiere a la información histórica acumulada por años en forma física, comúnmente sin respaldo y sin posibilidad de acceso rápido y expedito a ella. En las primeras 32 semanas de vigencia de la ley, según el informe n°8 de la Comisión de Probidad y Transparencia1 de noviembre de 2009, se han registrado 22073 solicitudes de información realizadas por ciudadanos y organizaciones a los diversos órganos del ejecutivo a los que se les aplica la norma, excluyendo a los municipios. De la investigación realizada (ver anexo 3) se desprende que no han tenido mayor dificultad para responder en tiempo y oportunidad cuando la información requerida corresponde a una antigüedad no mayor a 3 años. Esta situación se revierte cuando la información tiene una antigüedad superior a los 3 años. Y mientras más antigua es la información solicitada, más dificultoso es responder al requerimiento en forma rápida, eficiente y confiable. Para abordar esta necesidad Digital Systems, empresa orientada al desarrollo de tecnologías de la información y al diseño de sistemas de administración y procesamiento de datos para las empresas y organizaciones en general, ha diseñado una solución tecnológica para responder a la obligación que genera la 1 Informe n°8: http://www.leydetransparencia.cl/index.php?option=com_content&view=article&id=17&Itemid=7 Diciembre 30, 2009 Digital Systems Plan de Negocios MBA -ICCI 3 Ley de Transparencia a los órganos del Estado, específicamente las obligaciones que están asociadas a Transparencia Pasiva. El servicio consiste en el desarrollo de una Biblioteca Digital en la que se almacena la información documental, la que se organiza según una estructura y se le implanta un motor de búsqueda que permite realizar búsquedas exactas y rápidas. El mercado lo constituyen inicialmente los cerca de 620 órganos del Estado definidos por la normativa (ver anexo 2). Posteriormente ampliaremos la operación a las demás organizaciones públicas que no están sujetas a esta obligación (empresas públicas, poder judicial, poder legislativo y órganos contralores) y a las organizaciones privadas que operan en Chile y en países de Latino América para las que una solución como la planteada puede representar una solución que agrega valor a sus operaciones. La propuesta de valor se basa en que genera ahorros de dinero por la eliminación del almacenamiento de documentos físicos que implica; permite ahorros de espacio por el que se libera generando usos alternativos; y de tiempo por la posibilidad de encontrar rápidamente lo que se requiere. Esto redundará en no sólo cumplir con la ley y disminuir costos, sino que cumplir con calidad, promoviendo el uso de tecnología para el servicio más eficiente y expedito de los usuarios. Requiere de baja inversión; tiene buen retorno, proyectándose utilidades desde el año 2 de operación por más de $30 millones, superando el año 4 los $100 millones. Se ha transformado en una necesidad creciente para los órganos del Estado por la obligatoriedad de la norma y la inexistencia de diseño y sistemas para gestionar dicha información. Diciembre 30, 2009 Digital Systems Plan de Negocios MBA -ICCI 4 El equipo gestor cuenta con experiencia en el diseño y desarrollo de sistemas documentales digitales y bases de datos electrónicas, además del conocimiento de los clientes y de su estado de necesidad.

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28

Guan, Yang. "Dynamic modeling and capacity control of multiple chiller systems." Thesis, 2005. http://spectrum.library.concordia.ca/8580/1/MR10218.pdf.

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Multiple chiller systems are widely utilized for space cooling in industrial and commercial buildings. Good chiller control methods could offer benefits to users for more energy savings. Matching the anticipated cooling load and achieving higher coefficient of performance (COP) are the main objectives of multiple chiller capacity control strategies. With this as a main motivation, a dynamic model of compressor refrigeration chiller (CRC) and design of a closed loop PI controller for single CRC and multiple CRC systems are presented in this thesis. The dynamic model of vapor compressor refrigeration system includes thermostat expansion valve, evaporator, compressor, compressor motor, and condenser. The model equations were solved and open loop simulations were made to evaluate the time response characteristics of each component and whole chiller system under varying cooling load. A PI controller was designed and output responses of supply water temperatures, refrigerant mass flow rate and compressor motor rotor speed were studied.

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29

Huang, Jian-He, and 黃建和. "Applying Genetic Algorithm to Optimal Loading for Hybrid Chiller Systems." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/39d3cm.

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碩士
國立臺北科技大學
能源與冷凍空調工程系碩士班
104
With current innovation and development of chillers, there are various available chiller units on the market. Now the air conditioning systems are mostly designed as mixing chiller with large-capacity unit collocating small-capacity unit, while large-capacity unit usually are centrifugal and small-capacity unit are screw. The operation mode of this combination is mainly a subjective decision of site operators. During the peak period or with crowds they will launch large-capacity unit, otherwise launch small-capacity unit. Judged by operator is not the best operation method, because after a period of operating, due to efficiency decreasing of heat exchanger, piping position difference, shortage of refrigerant, uneven water pumps supply, inconsistent booting order and operation time and others, various chiller units have differences in performance. This study takes a large public museum as subject, applying Screw Chiller and VSD Screw Chiller, as well mixing centrifugal chiller with human subjective operations. To realize the characteristics of running chiller unit, it must be monitored and data parameters be recorded in long term, and then built a power consumption model of chiller using regression analysis. However, different types of chillers are with different limitations. Screw Chiller needs to be segmented to distinguish load factors, while paying attention to the lowest limit of Hertz of its inverter of VSD Screw Chiller; the surge effect of Centrifugal Chiller under the low loading is needed to be noted. Finally, the study uses genetic algorithm to calculate the load optimization of chiller unit which meets the spatial loads, then figure out the operation mode of chiller unit with minimum power consumption and improving efficiency of subject judgments. Results show that, Genetic Algorithm is a better way than subjective judgments and operation. When the spatial load is during 95% to 55%, the efficiency of energy saving is 4.6% to 24.4% respectively, and average efficiency of energy saving is 14.6%.

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Yang, Sheng-Da, and 楊昇達. "Study on the Energy-effective operation for air-conditioning chiller systems." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/79857596213523002155.

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碩士
國立臺灣科技大學
電機工程系
103
As the air-conditioning electricity consumption of the total electricity consumption of a considerable proportion, among the largest chiller energy consumption, since each chiller units in operation time, maintenance conditions and factors affecting the pipeline configuration, etc. Next, after a period of operation, the performance of each chiller will differ from both, so a chiller operation viable strategies to save energy. Using past experience to all operators of the operation, the traditional control strategies metropolis is provided by the original number, according to the analysis method when used as energy, but in this study using actual operating data to establish each chiller system operation parameters, and then using genetic algorithms to build the chiller load optimization of the strategy, it does not need to rely too wide operating range and performance curves incorrect conduct uncertain settings. So if under way to simulate the calculation for the actual operation of the air conditioning system of each element simulations to calculate the different loads, power, sort of performance to make a plan for the operation strategy, not only can save the power consumption of each component of the foreign operation , it can achieve the best air conditioning system design, and thus achieve the purpose of saving energy.

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31

Lin, Ei-Wei, and 林逸偉. "Energy Saving of the VWV Control Strategy, as Applied in Chiller Systems." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/72980993105211132466.

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碩士
國立勤益科技大學
冷凍空調系
99
Since the industrial revolution, overuse of energy has resulted in global warming, which further leads to abnormal climate change, and the counterattack phenomenon of nature has continuously caused serious disasters throughout the world. According to the statistical data of experts and scholars, fossil fuels will face depletion within 40 years. At present, 97% of the energy in Taiwan depends on imports from overseas countries, and the energy crisis is closely related to society, therefore, "energy saving and carbon emission reduction" is an imperative subject. In Taiwan, in an ordinary office building, energy consumption of the air-conditioning system accounts for more than 60% of the total power consumption of the building, thus, effective energy-saving improvement of existing air-conditioning systems is the most direct and effective method for overall energy-saving benefits. This study aimed to improve the air-conditioning system in an office building of D plant in southern Taiwan by applying the primary variable ice water volume and variable cooling water volume system to the chiller of the air-conditioning system. The system was supported by a frequency converter, a digital controller, control strategies, and other auxiliary methods. This study also analyzed and investigated the energy-saving benefit of a traditional constant water volume system. The results showed that, if both the primary variable ice water volume and variable cooling water volume system were used, total energy consumption of the air-conditioning system could be saved by 16%

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32

Yeh, Ching-Hwa, and 葉清華. "The Use of Efficiency Zoning as a Control Strategy for Multiple Chiller Systems." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/sv7gb9.

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碩士
國立臺北科技大學
能源與冷凍空調工程系碩士班
99
For larger air-conditioning systems, combinations chiller units are often used to improve the operating efficiency. As the COP of a water chiller at part load is significantly different from that at full load, effects of partial load control on the energy performance are investigated by COP zoning at part load. This research uses a typical building case in Taipei. The computer program eQUEST is used to obtain the monthly average air-conditioning load for the building case. Average and percentage distribution chiller loads strategies are used for the combination of chiller load. The average COP of the chillers at each range of partial load is used for multiple chillers system control. It has been found that using the average COP zoning analysis; the best control would allow the chillers to operate eight months in zone A, three months in zone B and one month in zone C. The average annual COP is 5.66, and the annual energy consumption is 504,136.1kWh. However for the worst control none of the monthly falls in zone A, but ten months fall in zone B and two months fall in zone C. The average annual COP falls in zone B. In comparison, the difference between the best and the worst cases are 22.7% and 20.7% respectively for the annual COP and annual chiller power.

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33

Lin, Yi-wei, and 林逸威. "A Study on an Energy-Saving Mechanism by Replacing Chiller Cooling Systems with Reserviors." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/60251701991148028590.

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碩士
世新大學
資訊管理學研究所(含碩專班)
100
Factories usually use cooling tower to be the cooling equipment for air system or production cooling system. This study is to explore the way to lower energy consumption since the energy cost is increasing by using cooling tower. This study is designed to use circulating water tower in top floor reservoir replace traditional cooling tower. Separated into experimental group and control group, analyze the feasibility of using sustained water use on top floor reservoir instead of traditional cooling tower to compare each energy saving result. The study focuses on using sustained water use on top floor reservoir and the property of tap water normal temperature instead of traditional way by using cooling tower to do the research. The temperature will get increasing by heat exchange on traditional cooling tower, relatively the increasing temperature will lower chiller performance and cause power consumption. Explore the temperature into the water and volume of usage from top floor reservoir, compare performance of chiller with traditional cooling towers, and do the comparison on the power use by two circulating cooling modes. Experimental group costs about NTD 3 millions and control group costs about NTD 3.7 million, the difference is about NTD782 thousand. According to the cost variance, it shows that using water reservoir to be cooling system can totally replace traditional cooling tower, and also provide energy saving and cost saving.

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LIN, JIN-ZHOU, and 林晉州. "Applying Cascade Neural Network and Simulated Annealing to Optimal Loading for Hybrid Chiller Systems." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/qsk546.

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碩士
國立臺北科技大學
能源與冷凍空調工程系
107
Manual method currently used is not efficient, resulting in wasted large amounts of energy. If we can use optimal chiller loading method to meet the system requirements , the total power consumption of the chillers will be minimized. This study uses the cascade forward backpropagation network to establish chiller power consumption models, which considers the operating constrains of each chillers. Simulated annealing is also integrated while satisfying cooling load conditions to optimize chiller loading.The simulation result show that integrating cascade forward backpropagation network and simulated annealing between 95% and 55% cooling loads improved power saving compared to manual method load distribution, saving maximum total power consumption by approximately 19% in75% load. Compared with the application of cascade forward backpropagation network integrated with genetic algorithm, the maximum error is about 3.4%, The results of the two algorithms are not much different, but the calculation time difference is about more than 1 minute.

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35

Hung, Shi-Je, and 洪士哲. "A Study of the Energy-Saving Optimization of Water Chiller Systems Using the Neural Network Strategy." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/15873518562398432148.

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碩士
國立勤益科技大學
冷凍空調系
99
The water chiller is the major component of a central air conditioning system, requiring about 40% of the total power consumption of a central air conditioning system. The major parameters that influence the efficiency of a water chiller system are the cooling water pump frequency, the outside air wet bulb temperature, the operating frequency of the cooling tower fan, the high pressure of the compressor and the cooling inlet water temperature. This study investigated how to use a neural network to integrate, train and simulate these parameters in order to create the optimal energy-saving mode. This study used a neural network and MATLAB to analyze the data collected by the field sensor according to the field load changes, simulated and adjusted the operating frequency of the cooling tower fan, and finally set up an effective module for predicting the cooling inlet water temperature and optimizing the water chiller load allocation, so as to reduce the power consumption of the water chiller in partial load runs and save energy.

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36

Silva, Fábio Manuel Barros e. "Desenvolvimento de um chiller usando como fonte de calor a energia solar." Master's thesis, 2017. http://hdl.handle.net/1822/46554.

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Dissertação de mestrado integrado em Engenharia Mecânica
A presente dissertação descreve o estudo sobre o desenvolvimento de um sistema de refrigeração de baixa potência, com a particularidade de poder também produzir energia elétrica, através do aproveitamento da energia solar. O estudo foi proposto pela empresa MFactor3 com objetivo de aferir a possibilidade de construção e comercialização do equipamento, mediante os resultados obtidos. O equipamento, comummente designado de chiller, funciona segundo o ciclo de absorção de simples efeito e utiliza a mistura de água e amoníaco como fluido de trabalho. Inicialmente será feita uma revisão bibliográfica relativamente à tecnologia de refrigeração por absorção, com referência aos equipamentos existentes e seu princípio de funcionamento. Será também abordado o estado da arte no que diz respeito às formas de aproveitamento da energia solar e respetivos campos de aplicação. Em relação à produção de energia elétrica, será feito um apanhado geral relativamente à legislação que regulamenta as unidades de microprodução para consumo próprio. Posteriormente será caracterizado em detalhe o funcionamento de um chiller de absorção de água e amoníaco, enumerando componentes e suas características principais. Será dado grande ênfase ao ciclo termodinâmico em estudo, e à forma com as pressões de operação, fluido de trabalho e fonte de calor influem no desempenho do equipamento. Outro aspeto relevante será o estudo de qual a melhor alternativa relativamente à colocação de um elemento capaz de produzir energia elétrica no sistema, e de como este pormenor influirá no desempenho global. A componente prática desta dissertação passará pela modelação do equipamento em software Aspen HYSYS, por forma a prever o comportamento do sistema em situação real. Os resultados obtidos serão acompanhados por uma breve análise de custos, comparando o sistema projetado com outros já existentes, por forma a aferir a real mais-valia da construção e comercialização do equipamento.
The present dissertation describes the study on the development of a low power refrigeration system, with the particularity of being able to produce electric energy through the use of solar energy. The study was proposed by the company MFactor3 with the objective of assessing the possibility of construction and commercialization of the equipment, through the results obtained. The equipment, commonly referred to as a chiller, operates according to the single-effect absorption cycle and uses the water-ammonia mixture as the working fluid. Initially a bibliographic review will be made regarding absorption refrigeration technology, with reference to existing equipments and their operating principles. State-of-the-art will also be addressed with regard to the ways in which solar energy is used and its fields of application. In relation to the production of electricity, a general overview will be made regarding the legislation that regulates microproduction units for own consumption. Subsequently, the operation of a water and ammonia absorption chiller will be characterized in detail, enumerating components and their main characteristics. Emphasis will be given to the thermodynamic cycle under study, and to the ways that operating pressures, working fluid and heat source influence the performance of the equipment. Another relevant aspect will be the study of the best alternative to the placement of an element capable of producing electrical energy in the system, and how this detail will influence overall performance. The practical component of this dissertation will be the modeling of the equipment in Aspen HYSYS software, in order to predict the behavior of the system in real situation. The results obtained will be accompanied by a brief cost analysis, comparing the projected system with other already existing ones, in order to gauge the real added value of the construction and commercialization of the equipment.

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37

Lee, Jia-Chu, and 李家居. "Load Distribution Optimization on Chiller Units of Heating, Ventilation and Air Conditioning Systems by Using Quantum Genetic Algorithm." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/48893274820833129447.

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博士
國立中山大學
電機工程學系研究所
101
Traditionally and commonly, the Optimal Chiller Loading (OCL) distribution method includes the Average Loading (AVL), Lagrangian Multiplier (LGM), Genetic Algorithm (GA), Particle Swarm Algorithm (PSA) methods etc. These above methods all have several disadvantages for accuracy computation. However, the Genetic Algorithm Method can overcome disadvantages that the Lagrangian Multiplier Method can not such as converge in the low-load regions, so it is very difficult and complicated to evaluate the program. Therefore, the Genetic Algorithm Method is not satisfactory to find optimal solutions. Moreover, the computation of adopting Particle Swarm Algorithm is nearly the same efforts on the load ratio （Zi） and power consumption （Total Power）. Also, it is not the optimal algorithm in fast convergence data on Chiller Units demand-side. This study of paper offers a method by means of Quantum Genetic Algorithm to improve on these faults. Quantum Genetic Algorithm can not only the improve disadvantage that the Lagrangian Multiplier Method cannot converge in low-load rates, but also to solve problems where the Genetic Algorithm method cannot find optimal solutions, and to modify the Particle Swarm Algorithm cannot fast converge in more short time on the iterating computation in numbers. This study adopts the Quantum Genetic Algorithm to solve the optimal chiller loading distribution problems. The main objective function is also defined using power consumption, and the partial loading ratio of each chiller unit is considered as the ideal parameter. In the results of two case studies on Chiller Units, the Quantum Genetic algorithm overcomes the weakness of the Lagrangian Multiplier Method where the system may be divergent at low demands, and reduces the amount of power consumption leading to more economical outgos than that adopted via the Genetic Algorithm or Particle Swarm Algorithm etc.

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38

Chen, Bo-Yuan, and 陳柏淵. "A Study of the Energy-Saving Optimization of Water Chiller Systems By Using the General Regression Neural Network And Random Forest." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/66z942.

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碩士
國立臺北科技大學
能源與冷凍空調工程系
106
In recent years, With the rapid development of information technology, Data Mining has been used in many fields to find to effectively and correctly analyze the massive data has become an important issue.According to the Energy Bureau of the Ministry of Economic Affairs, air-conditioning energy consumption accounts for more than 40% of the energy consumption of the entire building, and the energy consumption of chiller plant accounts for about 60% of the energy consumption of air-conditioning systems. Therefore, how to make the Chiller Water host operate at high efficiency is a very important research topic. In engineering applications, the predictive models are always adopted to solve the actual problems. Therefore, the aim of this thesis is to study how to build up a high accuracy predictive model according to the historical data in engineering applications. In this study, R software was used in conjunction General Regression Neural Network combine Random Forests package. After the model and performance evaluation were established, the wet-bulb temperature range and approach temperature were set.Analyze the optimal start-up combination and evaluate the follow-up operation strategy of the Chiller Water master. After using the actual field data for analysis,in 200~400 RT、400~600RT、1800~2200RT and Wet-bulb temperature24~26℃、26~28℃、27~29℃. By changing the operating parameters, The energy-saving rate can reach 2.47~19.39%. the results prove the importance of chiller start-up operation strategies.

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39

Powell, Kody Merlin. "Dynamic optimization of energy systems with thermal energy storage." 2013. http://hdl.handle.net/2152/21590.

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Thermal energy storage (TES), the storage of heat or cooling, is a cost-effective energy storage technology that can greatly enhance the performance of the energy systems with which it interacts. TES acts as a buffer between transient supply and demand of energy. In solar thermal systems, TES enables the power output of the plant to be effectively regulated, despite fluctuating solar irradiance. In district energy systems, TES can be used to shift loads, allowing the system to avoid or take advantage of peak energy prices. The benefit of TES, however, can be significantly enhanced by dynamically optimizing the complete energy system. The ability of TES to shift loads gives the system newfound degrees of freedom which can be exploited to yield optimal performance. In the hybrid solar thermal/fossil fuel system explored in this work, the use of TES enables the system to extract nearly 50% more solar energy when the system is optimized. This requires relaxing some constraints, such as fixed temperature and power control, and dynamically optimizing the over a one-day time horizon. In a district cooling system, TES can help equipment to run more efficiently, by shifting cooling loads, not only between chillers, but temporally, allowing the system to take advantage of the most efficient times for running this equipment. This work also highlights the use of TES in a district energy system, where heat, cooling and electrical power are generated from central locations. Shifting the cooling load frees up electrical generation capacity, which is used to sell power to the grid at peak prices. The combination of optimization, TES, and participation in the electricity market yields a 16% cost savings. The problems encountered in this work require modeling a diverse range of systems including the TES, the solar power plant, boilers, gas and steam turbines, heat recovery equipment, chillers, and pumps. These problems also require novel solution methods that are efficient and effective at obtaining workable solutions. A simultaneous solution method is used for optimizing the solar power plant, while a static/dynamic decoupling method is used for the district energy system.
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40

Yang, Cheng-Jin, and 楊政瑾. "Applying Wavelet Neural Network to Predict Chiller Performance for a Variable Chilled Flow System." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/e3zu73.

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碩士
國立臺北科技大學
能源與冷凍空調工程系碩士班
104
This thesis, using the same benchmark, analyzed and compared the simulation results from three predictive models which were based on three methods respectively, i.e. wavelet neural network, multiple linear regression and back propagation neural network. The subjects of this experiment were conducted on two centrifugal chillers at a specific site. The analysis and comparison results showed that all the three methods produced fairly accurate predictive simulations. In which the wavelet neural network approach was superior to both the multiple linear regression and back propagation neural network ones in all evaluated values, such as R^2 coefficient of determination, root mean square error (RMSE), mean absolute percentage error (MAPE). From the simulations results, we assure that the wavelet neural networks can be applied to predictive modeling for air conditioning systems. This thesis further examined how changes in chilled water flows affect chiller performance. For chilled water pumps in chillers, reduced chilled water flows can definitely lower their power consumption. For evaporators, however, this leads to changes in heat transfer coefficients and potential changes in evaporation temperatures, and then potential changes in the coefficient of performance (COP) of chillers. To prove the impact of chilled water flows on chiller performance, this study applied the predictive modeling based on wavelet neural networks to air conditioning verification patents and examined how changes in chilled water flows in the two chillers at the site affected the COP of the chillers. As found in the subsequent results, the COP of Chiller No. 1 improved about 7-8% when the chilled water flow was increased about 12.7% during its actual operation. In contrast, the COP of Chiller No. 2 had a decline of about 5-6% as the chilled water flow was dropped 19%. This proves that changes in chilled water flows actually can affect the chiller performance.

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41

Goodheart, Kevin A. "Low firing temperature absorption chiller system." 2000. http://catalog.hathitrust.org/api/volumes/oclc/47214789.html.

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Thesis (M.S.)--University of Wisconsin--Madison, 2000.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 157-158).

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42

莊孟軒. "Optimal operation model analysis of secondary chilled water pumps and centrifugal chillers for air-conditioning system of semiconductor manufacturing." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/77476390213969778341.

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碩士
國立臺北科技大學
冷凍與低溫科技研究所
92
Energy crisis is a common problem, which will be encountered by all the human beings in the future. In these years, various devices and methods for energy saving is continually developed. Of course, includes using in air conditioning system. In summer, air-conditioner consumes 40%~50% of total electricity in general office building. In electronics manufactory, the power consumption of air-conditioner reaches to 30%~45%, that is quite huge. Accordingly, air conditioning system belongs to one of the heavy power-consumption device. Taiwan locates in subtropical zone and has specific climate in each season. When summer comes, the power consumption of air conditioning system is steadily on the increases. However, the winter has obviously discrepancy temperature with summer. Not only temperature but also the cooling load ratio decreases. Thus, a good distribution for cooling load is quite important. The Air-Conditioning system in a semiconductor manufactory is keeping a constant chilled water supply temperature and flow rate of chiller, then control secondary chilled water pump’s flow rate with inverter that depend on cooling load changes. Because the power consumption proportion of chiller in HVAC system is the highest. And chilled water supply temperature’s setting will change the energy consumption and performance of chiller. At the same time, it also influence the power input of secondary chilled water pump directly. This thesis will probing into the relationship between centrifugal chiller and secondary chilled water pump, possible to make up operation fitness and running in a optimal module. That’s just what we expected.

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43

Hua, Dong-I., and 董一華. "Improvement inOil Recyclable System ofFlooded Water Chiller." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/79527027991253272369.

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碩士
中原大學
機械工程研究所
96
Abstract In this study, we apply a flooded water chiller in the cooling of silicon manufacture procedures. We take R-134a as refrigerant for the chiller system and choose desired compressor with a professional software package. We also design the evaporator with a heat exchange design tool and the flooded water chiller with theoretical and practical experiences. A jet pump is adopted in the oil recyclable system to push the refrigerant oil of evaporator back from heat exchanger to the input of compressor. Finally, we try to validate the system capacity using CNS12575 as standards together with stability test. Furthermore, we also monitor the system running for 6 months. The results indicate that the cooling capacity of flooded water chiller satisfies the national standards of 2005. The reliability of improved oil recyclable system is also satisfactory in the 6-month validation.

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44

Chao, Hsu Sheng, and 徐聖朝. "Research of Saving Energy of Cleanroom Chiller System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/95974052322233290807.

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碩士
明新科技大學
精密機電工程研究所
102
In recent years, due to the energy crisis let us realize the limited nature of resources and sustainable development of the planet. Taiwan's economic development main fore is high-tech industries, especially semiconductor and optoelectronics. Taiwan’s energy relies on imports, in order to survive Earth and enhance the competitiveness of enterprises; saving energy seems important and urgent. There are factories spread all over science parks, and many companies still keep building new factories. Most of factories that have cleanroom run 24 hours all of the year. We observe the energy demand in large factories find out that AC system needs most power consumptions. According to that, this thesis research about cleanroom temperature control system: First, testing cooling water at different temperature at 26.5℃, 28.5℃, 30.5℃ and 32.5℃, and comparing how different power consumptions that chiller load, then find out the optimization operation point; Second, use the cooling water that temperature at the chiller is optimization operation, and find out the optimization water flow by observe chiller’s power consumptions in different cooling water flow; Finally, testing power consumptions that once run 3 chillers when they set up side by side, then know different run set cause different power consumptions. This research find when chiller’s operation loads at 70%~100% saving more energy. Optimization operation load of chiller should use cooling water temperature at 26.5℃ and set chiller load at 90%. When the pump of cooling water at 56Hz, cooling water flow 14577LPM, can save more energy. Besides, comparing power consumptions that run different chillers side by side find energy saving effect reach 1.31%, and don’t need to spend extra cost. It because when chiller run has more area to dissipate heat can lower the power consumptions of chiller. Keyword: cleanroom, chiller, temperature control, energy saving.

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45

Trautman, Neal L. "Chilled Water System Modeling & Optimization." Thesis, 2020. http://hdl.handle.net/1805/23572.

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Indiana University-Purdue University Indianapolis (IUPUI)
The following thesis looks into modeling a chilled water system equipped with variable speed drives on different piece of equipment and optimization of system setpoints to achieve energy savings. The research was done by collecting data from a case-study and developing a system of component models that could be linked to simulate the overall system operation.

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46

Hsieh, Chih-Ming, and 謝志明. "A Study of Evaluation System for Green High Tech Factory Building Chiller System." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/75505644161030345090.

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碩士
國立勤益科技大學
冷凍空調系
102
Green High-Tech Factory Building Chiller System is applied in a wide range of industrial applications. This study focus on the energy consumption of the Chiller System of a thin film transistor liquid crystal display (TFT-LCD) industry. Under 24 hours a day and 365 days a year of operation for production, there will be a decay of energy performance and Refrigerant leakage issues, which will increase the operating cost. It is essential to save energy consumption and operating cost of Chiller system in TFT-LCD industry. This paper analyzes the energy consumption of Chiller system of an optical plant in Central Taiwan Science Park. Proceed a series of system energy saving analysis, adjustment, testing, including analysis of outside air condition, analysis of chiller system control optimization, analysis of cooling tower control optimization; through adjustment of compressor operation, adjustment of system pressure difference and adjustment of chiller water temperature to improve efficiency of chiller system operation. Besides, by using adjustment of cooling tower leaving water temperature controlling model to achieve reduction of system energy, through a long term record of each item operating data of the system and change of power consumption. Chiller system can be reduced about 5%. It reveals that the energy saving strategies could be achieved through the field measurement and robust investigation specific for Chiller systems.

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47

Rawlins, Cecil Alexander. "Insulation of chilled water reticulation systems in underground mines." Thesis, 2013. http://hdl.handle.net/10539/12788.

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48

Chang, Ming-hui, and 張明輝. "Case study of chiller performance improvement for HVAC system application." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/11496080209532229806.

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碩士
國立勤益科技大學
冷凍空調系
97
As for advancement of technology, energy conservation and environmental issues becomes more significant. 17％ of total energy annual consumption is consumed from commercial building and one third of them is consumed on HVAC system. Therefore, it is vital and meaningful to pay more attention on energy consumption of HVAC system as well as on chiller systems. In this study, cases studies including different control strategy chillers were conducted to evaluate the energy conservation potential. Strategic plans including chiller schedule control, variable primary flow application and chiller shift control were investigated comprehensively through cases study of HVAC system. Energy consumption dates were recorded and analyze sized from on-site real-time measurement or web-based monitoring. The results reveal that energy-saving for a HVAC system cannot only rely on high performance chiller, but also the appropriate control strategy specific for the building. It is expected that this study will stimulate a more robust investigation of energy-efficient and cost-effective chiller system specific for HVAC system in commercial building project.

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49

ni, Pj, and 倪萍均. "System planning and operation cost analysis of heat recovery chiller." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/27506950650044491002.

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碩士
國立勤益科技大學
冷凍空調系
97
ABSTRACT The different heat recovery chiller mode and chilled water system are studied to analyze the three different heat recovery modes and various design of chilled water piping. The recovered heat is kept above the minimum requirement under light air conditioning load. The energy consumption and carbon dioxide emissions of the conventional chiller with various boilers are compared with the heat recovery chiller to verify its economical and environmental value in the air conditioning systems. A heat recovery chiller used in a full make-up air cleanroom system is analyzed during January 2009. The energy cost and carbon dioxide emissions are studied. The cost and carbon dioxide emission of conventional chiller with electric heater is 10.64 times of the heat recovery chiller. The cost of conventional chiller with Diesel boiler is 12.31 times of the heat recovery chiller, while the carbon dioxide emission is 5.6 times. The cost of conventional chiller with natural gas is 8.73 times of the heat recovery chiller, while the carbon dioxide emission is 4.49 times. The results show that the proper design of air conditioning system will save the energy and reduce the carbon dioxide emissions.

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50

Chu, Cheng-Yu, and 朱正宇. "Application of Grey System Theory to Predict Chiller Power Consumption." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/7md3dw.

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碩士
國立臺北科技大學
能源與冷凍空調工程系碩士班
95
98% of the energy needed in Taiwan has been imported. The prices of petroleum and electricity have been increasing. In addition, facility capacity, amount of electricity generation, amount of electricity consumption and number of Taiwan Power Company customers have continued to increase. For these reasons energy conservation has become an important topic. In the past linear regression was used to establish the power consumption models for chillers. In this study, grey theory is used to evaluate the power consumption of a chiller so as to lower the total power consumption at peak-load (so that the relevant power providers do not need to keep on increasing their power generation capacity and facility capacity). In grey theory, only several numerical values (at least four numerical values) are needed to establish a GM(1,N). If PLR, the temperatures of supply chiller-water and return chiller-water, and the temperatures of supply cooling-water and return cooling -water are taken into consideration, quite accurate results (with the accuracy close to 99% for short-term predictions) may be obtained. Through such methods, we can predict whether the power consumption at peak-load will exceed the contract power capacity signed by the corresponding entity and Taiwan Power Company. If the power consumption at peak-load exceeds the contract power capacity, the temperature of the supply chiller-water may be adjusted so as to reduce the PLR and hence lower the power consumption.

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