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PEREIRA, Gutenberg da Silva. "Análise numérica e experimental de sistema de ar condicionado em edifícios verdes." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/19556.
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Previous issue date: 2016-02-22<br>Com a atual escassez de energia, alta demanda e aumento do custo da energia elétrica,
verifica-se que uma questão importante é a melhoria da eficiência dos sistemas de
climatização dentro de um padrão de eficiência certificado possibilita-se, assim, para uma
comparação real de qual é a melhor opção de layout e operação dos sistemas, já que os
sistemas de climatização são responsáveis por uma alta parcela do consumo energético.
O presente trabalho se propõe a comparar dois sistemas de refrigeração diferentes, usando
chiller de compressão de vapor, para a climatização de ambientes. Foram propostas
diferentes modalidades para a comparação em operações isoladas e ações combinadas.
Essas operações são avaliadas nos conceitos de edifícios verdes. Foi desenvolvido um
modelo matemático baseado nos princípios de conservação de massa e energia,
complementado por várias funções, de modo a determinar as propriedades termofísicas e
eficiências dos compressores. O modelo avalia a influência dos parâmetros operacionais
principais do sistema de refrigeração a água gelada operando em três configurações
diferentes. As equações do modelo foram resolvidas pelo programa EES (Engineering
Equation Solver). Os resultados mostraram que o sistema com compressão diferenciada
apresenta COP igual ao do sistema com chiller parafuso na faixa de 0 a 300 TRs, e um
COP superior em média de 9% na faixa de 400 a 800 TRs.<br>With the current energy shortages, high demand and rising cost of electricity, it turns out
that an important issue is the improvement of the air conditioning efficiency within a
standard of efficiency certificate for a real comparison of what is the better layout option
and operation of systems, as the HVAC systems account for a high share of energy
consumption. This study aims to compare two different cooling systems using vapor
compression chiller for air conditioning environments. They were different proposals
modalities for comparison in isolated and combined action operations. These transactions
are valued on the concepts of green buildings. A mathematical model was developed
based on the principles of conservation of mass and energy, supplemented with various
functions in order to determine the thermophysical properties and efficiencies of the
compressors. The model evaluates the influence of the main operating parameters of the
cold water cooling system operating in three different configurations. The model
equations were solved by EES program (Engineering Equation Solver). The results
showed that the system presents differentiated compression COP equal to the screw
chiller systems in the range from 0 to 300 RTs and a higher COP (average of 9%) in the
range of 400 to 800 TR.
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Casetta, Damien. "Modèle d'aide à la conduite de réseaux de froid." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM012.
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La maîtrise de la demande en climatisation des bâtiments tertiaires peut contribuer à la limitation du réchauffement climatique à 2°C. Les réseaux de froid urbain sont une solution pour répondre à cette demande avec une haute efficacité énergétique. Une conduite performante est cependant essentielle pour maintenir et augmenter leurs avantages compétitifs. L'objectif de la thèse est de contribuer à la construction d'un outil d'aide à la conduite journalière des réseaux de froid. La difficulté réside à deux niveaux : la diversité des décisions et la complexité des phénomènes physiques sous-jacents. L'originalité est de proposer une méthodologie pour aider au pilotage des groupes frigorifiques, des tours aéroréfrigérantes, de la pression différentielle et de la répartition de puissance entre des centrales de production aux performances variables. La méthodologie développée est appliquée au réseau de froid de Paris-Bercy exploité par Climespace. Tout d'abord, un modèle intégrant une représentation physique des centrales de production, du réseau de distribution et des sous-stations, est développé. En particulier, un modèle de type semi-empirique, paramétrable sur des mesures, est modifié pour calculer les performances non-nominales des groupes frigorifiques centrifuges. La validation du modèle complet est réalisée sur un jeu de données indépendant de l'identification. Ensuite, le modèle est exploité pour rechercher une conduite optimisée à partir d'un modèle de prévision de la demande. La méthode proposée est séquentielle : résolution a priori des optimisations locales puis génération de modèles quadratiques de centrales servant à déterminer la répartition optimale. La pression différentielle est minimisée à partir de l'identification, par simulation, de la sous-station défavorisée. Enfin, la réduction de la consommation électrique est évaluée sur une semaine d'été<br>Cooling demand management of commercial buildings can contribute to limit global warming below 2°C. District cooling is an energy-efficient option. However, improving operational performance is of great importance to ensure and increase its competitive advantages. The aim of this thesis is to contribute to the development of a decision-support tool for daily operation of district cooling networks. Challenges lie at two levels: diversity of decisions to be taken and complexity of physical phenomena involved. The original aspect of our work is to propose a methodology to improve chillers and cooling towers control, differential pressure management and dispatching between production plants with variable efficiency. Our developments are applied to the district cooling of Paris-Bercy, operated by Climespace. First; a model featuring a physical description of chilled-water production plants, distribution network and buildings substations, is developed. In particular, a semi-empirical model with identified parameters is modified to compute non-nominal characteristics of centrifugal chillers. The system model is validated against an independent dataset. Then, the model is used to find optimized controls from cooling loads forecast. The proposed methodology is sequential: pre-computation of optimal set-points at plant level and then generation of quadratic plant models to solve the dispatching optimization problem at each time step. Differential pressure is minimized with a simulation-based tracking of the critical substation. To conclude, electricity consumption reduction with optimized controls is evaluated during a summer week
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Jui, Wang Wen, and 王文瑞. "Economic Validation of VFD Centrifugal Chiller." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/z6c66y.
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碩士<br>國立臺北科技大學<br>能源與冷凍空調工程系碩士班<br>100<br>Centrifugal chiller is the single largest Power consumptions in central HVAC system, Beside the chiller energy efficiency operation at 100% load, But make sure chiller operator at high efficiency at 50-60% part load of a chiller is critical to energy saving for a building performance . According the ARI standard 550/590-98 Integrated part Load Value. Non-standard Part-load Value (NPLV).Most of the Chillers operation 99% at part load condition , for the Multi-chillers plant room and all year chillers operation project required, VFD Chiller have huge advantage for the energy saving. VFD chiller consider as the best solution for the energy saving proposal.
This paper will use computer software to simulation variable frequency drive( VFD) and constant speed drive (CSD) chiller system design and energy consumption in Taiwan climate. The Coefficient of Performance (COP) and payback of a variable frequency drive (VFD) centrifugal chiller with constant speed drive (CSD) chiller.
Also establish base line operating conditions base on ESCO ASHRAE-G14-2002- chiller M&V menth-R-1.01-option B here in Taiwan, To establish base line CSD chiller performance data and base line data of VFD chiller after switch to VFD chiller for the project case to cross- reference with ARI computer simulation data. Analyzed results show that VFD chiller the capacity and performance can improve.
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Lung, Liu-Ching, and 劉青龍. "Economic Analysis of VFD Centrifugal Chiller." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/kcezqh.
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碩士<br>國立臺北科技大學<br>冷凍空調工程系所<br>93<br>Motors of chiller、cooling tower、pump and air handing units are the major part of electric power consumptions for HVAC system in normal building. When the building cooling load changed, Change the motor speed by variable frequency drive (VFD) is a good energy saving strange in recently years. Although commercial building largest single electric consumption is chiller. The relationship between variable frequency drive (VFD) and centrifugal chiller only can be seen in the paper study before. The large VFD (200~1200 HP) becomes more popular because cost down and performance improved. The technology of VFD centrifugal chiller becomes possible. This paper will use computer software to calculate chiller system design and energy consumption in Taiwan climate. Study the energy differences between the fix speed and variable speed centrifugal chiller in 4 seasons of a standard year. In order to set up a chillers economic analysis model for HVAC system. Design 4 different chiller tonnage combinations for a shopping center. Finding the best energy saving chiller’s design for this building. This chillers economic analysis model can help HVAC consultant and owner to find a good way know VFD centrifugal chiller saving energy for their building.
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鍾金龍. "The Study on Centrifugal Chiller Use Variable." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/72993855571894898287.
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碩士<br>國立臺北科技大學<br>冷凍與低溫科技研究所<br>90<br>Abstract
This study discusses both theoretical and practical differences between centrifugal chiller unit with fixed speed (FS) guide vane capacity control, and variable frequency drive (VFD). The centrifugal chiller unit selection program is based on McQuay rating program. Both FS and VFD units ranged from 702kw to 3510kw are selected for this study based on three conditions which respectively are (1).using ARI Standard : leaving chilled water temperature 6.7℃、entering condenser water temperature 39.4℃ and following the change of ARI condenser water temperature (2).using Taiwan customary standard : leaving chilled water temperature 7.0℃、entering condenser water temperature 32.0℃ and following the change of ARI condenser water temperature and (3). using Taiwan customary standard : leaving chilled water temperature 7.0℃ but entering condenser water temperature is fixed at 29.4℃. The analysis is made based on each unit’s COP、 IPLV、NPLV and price.
The summary of analysis as indicated as following :
1. Under full load, FS units have higher COP values than VFD units. It means FS units are more suitable for long duration of full load operation.
2. The COP of FS units will decrease dramaticly, when running at 50% load, but VFD units still keep the same COP from 25% to 75% load. Consenquently, VFD units are suitable for partial load operation.
3. VFD units cost 10% to 30% higher than FS units and its IPLV COP is highter than about 35%.
4. VFD units are able to keep the power factor at minimum 0.95 without power factor correction using capacitor.
5. In the large chiller plant, using the center cooling tower system, the entering condenser water temperature can’t be in accordance with ARI relief require. So VFD units can’t be used.
6. VFD units have better starting performance than traditional Y-△ starter and have built-in safety device.
7. VFD units are susceptible to the self generated harmonics problem. Care must be taken to eliminate effects of harmonics so as to avoid damage to the electrical power system.
As a whole, VFD units are vastly superior to FS units so VFD units should be widely marketed.
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Chen, Chung-Cheng, and 陳忠正. "Centrifugal Chiller Surging Prediction and Maintenance Strategy Development." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/uvfkv9.
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碩士<br>國立臺北科技大學<br>能源與冷凍空調工程系碩士班<br>101<br>The first killer is the surging of centrifugal chillers, can make a huge vibration, and causing critical parts damage and out of order. In cope with the surge of Centrifugal chiller, the best strategy to get avoid surge occurred 、extending the life time of critical parts、reducing energy consumption、and running operation cost is choosing the Predictive Maintenance preventive management in advance。
This paper have made a Predictive Maintenance study by means of the real experience knowledge and system analysis that focused on the surge of the market brand centrifugal chiller in order to make a follow analysis about early alert for the requirement of lowing surge rate and Bearing wear out。So that the chiller can apply self-diagnosis and detection tracking to keep a continue robust running as regards of controlling the efficiency of host chiller。From some practical surge case know that we can judge the chiller breakdown by the relationship of the adopted relative physical parameter of the centrifugal chiller like that : frozen oil temperature、bearing temperature、condenser inlet and outlet water temperature、 and refrigerant saturation temperature in condenser; in the mean time, can make some system explore and analysis for breakdown from long term operation。Finally，we hope people in the air conditioning field can have a available reference for judging breakdown of centrifugal chiller by means of the developed experience rule and breakdown analysis refer to the mentioned chiller。The report also provide the reliable information about when the chiller will happen breakdown，validated to carry out predictive maintenance so as to reach the target about upgrade the system sustained and stable operation。
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Hsiung, Lai Chien, and 賴建雄. "Remote Monitoring and Fault Diagnosis of Centrifugal Chiller." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/yc7n65.
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碩士<br>國立臺北科技大學<br>能源與冷凍空調工程系碩士班<br>104<br>The increasing running hours and poor repair of centrifugal chiller deteriorate the chiller equipment and increase the failure frequency, so that the faults increase, causing added burdens to the administrators and the manufacturers after-sales service. When the chiller has a problem, the user calls the manufacturer for help, the manufacturer sends a service engineer to the site for inspection and repair. In this process, the service engineer may carry improper tools and fittings, and the service engineer may fail to solve the problem on site, more senior maintenance personnel are required, wasting manpower and increasing cost.
This paper researches "Remote Monitoring and Fault Diagnosis of Centrifugal Chiller" based on Windows server architecture. The MS S.Q.L is used as background database, combined with NET program accessing. The temperature transmitter, ultrasonic flowmeter, outdoor temperature and humidity transmitters and power monitoring electric meter are integrated to collect field data, and the ZigBee wireless network is used for information transmission. The real-time operating information and historical query data are displayed in HTML webpage format on the webpage browser instantly for the field operators or remote administrators. The existing centrifugal chiller is changed into a remote monitoring and fault diagnosis system. The Cloud database is built by monitoring the chiller operating data in all weathers. The fault tree analysis is used to work out the minimum cutset, minimum path set, structure importance and critical importance.
This case plans to mount sensors in different positions of a government office building. The data are collected using ZigBee for convenience. The data are then transferred to the Cloud database via network, the system fault analysis and network communication functions are completed. The webpage is connected to the Cloud database, the charts and tables are displayed in the webpage. This study develops a remote monitoring, diagnosis, repair and management tool. It is proved that the remote monitoring and fault diagnosis architecture for chiller can provide beneficial experience and basic data for centrifugal chiller, it is worth popularizing and using to some extent.
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Chiang, Yen-Shin, and 江衍欣. "CFC Conversion and Performance Analysis on Centrifugal Chiller Plants." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/63702816001142064974.
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Wang, Yi-Hua, and 王逸華. "Research on Energy Efficiency of Frequency Magnetic Centrifugal Chiller in Hospital." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/g38384.
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碩士<br>國立臺北科技大學<br>能源與冷凍空調工程系碩士班<br>105<br>In this paper, the application of variable frequency magnetic centrifugal host in the hospital operation of the benefits of the study, due to the design of ice water mainframe tons of peak and multiplied by the future climate warming and other margin for the estimated number of air conditioning, but the actual Air conditioning load is not full year full load operation, so this study for part of the load period of research, the use of variable frequency magnetic centrifugal ice water mainframe used in part of the load operation.
Therefore, this paper to a hospital air conditioning system as an example, before and after the replacement with the central monitoring system using the daily record of electricity consumption for numerical analysis, and the required electricity to do the comparison, before and after the average monthly consumption Power savings of about 34.6%, due to the frequency of magnetic vacuum centrifugal ice water host performance and energy efficiency for the air conditioning industry and engineering designers have not fully revealed, the results of this paper can provide these professionals in the design phase selection ice water host When the important reference, in order to more commonly used variable frequency unit as an effective means of air conditioning system energy.
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Yu, Pen-Liang, and 游本良. "The experimental analysis of the effect of cooling water and chilled water temperature on centrifugal chiller performance." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/52241047062254270434.
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碩士<br>國立中央大學<br>機械工程研究所碩士在職專班<br>94<br>Taiwan is located in the subtropical area with hot and humid climate in the summer. It requires a large number of air conditioning facilities. The chilled water is used to control the temperature and humidity in the industry, especially for the clean room to maintain the constant temperature and humidity. The chiller is the heart of the chilled water system, and its efficiency has a great influence on consumption of the energy.
This research experimentally studies the performance of the chiller in different water temperature. The Taguchi method is used to analysis the results of the experiments. From the operation data of the TFT-LCD factory, a linear regression of the chiller’s COP versus its condenser inlet water temperature can be found. The result shows that the COP of the chiller will increase with decreasing condenser inlet water temperature. Because the variation of chilled water temperature tested is too small, the effect of the chilled water to the COP is not significant.
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Hsu, King-Huei, and 徐金輝. "A Study on Energy Saving Performance of Variable Frequency Drive Centrifugal Chiller." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/g3fktr.
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碩士<br>國立臺北科技大學<br>冷凍空調工程系所<br>94<br>Centrifugal chiller is the single largest electrical load in central air-conditioning system. Energy efficiency of a chiller is critical to energy saving performance for a building. This thesis presents that the COP of a variable frequency drive (VFD) centrifugal chiller at operating conditions here in Taiwan is far better than a constant speed drive (CSD) chiller. An ARI certified computer program is used to simulate operation of two 350 tons centrifugal chillers, one is VFD and the other one is constant speed. Analyzed results show that COP of a VFD chiller operates between 100% and 40% load is up to 70% higher than that of the CSD chiller if ECWT drops to 20 ℃ from 30 ℃. COP can be further improved by resetting leaving chilled water temperature if relative humidity is not a concern. The conclusion of this thesis may provide some guidelines for those professionals when they make a selection of centrifugal chillers. Then VFD chillers may be more popularly applied in air-conditioning system design as an effective measure to achieve energy saving requirements.
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Tadros, Amir The University of New South Wales School of Mechanical & Manufacturing Engineering UNSW. "Performance and safety of centrifugal chillers using hydrocarbons." 2008. http://handle.unsw.edu.au/1959.4/41242.
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The high ozone depletion and global warming potentials of fluorocarbon refrigerants have resulted in prohibitions and restrictions in many markets. Hydrocarbon refrigerants have low environmental impacts and are successfully used in domestic refrigerators and car air conditioners but replacing fluorocarbons in centrifugal chillers for air conditioning applications is unknown. Hydrocarbon replacements need a heat transfer correlation for refrigerant in flooded evaporators and predictions for operating conditions, capacity and performance. Safety precautions for large quantities of hydrocarbon refrigerants are needed and control of overpressure in plantrooms requires accurate prediction. Reliable correlations exist for forced convection in a single phase flow, condensation outside tubes and evaporation off sprayed tubes. For flooded evaporators this thesis proposes a new correlation for forced convection boiling of any refrigerant. An enhancement factor is combined with a modified Chen coefficient using recent pool boiling and forced convection correlations outside tubes. This correlates within typically a factor of two to known boiling literature measurements for CFC-113, CFC-11, HCFC-123, HFC-134a and HC-601. The operating conditions, capacity and performance of replacement hydrocarbons in centrifugal chillers were predicted using fluorocarbon performance as a model. With the new heat transfer correlation hydrocarbon predictions for flooded evaporators were made. For any fluorocarbon refrigerant there exists a replacement mixture of hydrocarbons which with a rotor speed increase about 40% gives the same cooling capacity in the same centrifugal chiller under the same operating conditions. For example replacing HCFC-123 in a flooded evaporator with HC-601/602 [90.4/9.6] and increasing the rotor speed by 43% will increase the coefficient of performance by 4.5% at the same cooling capacity. The maximum plantroom overpressure considered was from leakage and ignition of a uniform air/refrigerant mixture with maximum laminar burning velocity. Flow was modelled using a turbulence viscosity due to Launder and Spalding and turbulent deflagration using a reaction progress variable after Zimont. These partial differential equations were solved approximately for two and three dimensional geometries using finite volume methods from the Fluent program suite. Simple overpressure predictions from maximum flame area approximations agreed with Fluent results within 13.7% promising safe plantroom design without months of computer calculation.
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HUANG, KAI-CHANG, and 黃凱章. "Study on Energy Performance of Magnetic Bearing Centrifugal Chiller Applied in Factory Buildings." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/n2m9x7.
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碩士<br>國立臺北科技大學<br>能源與冷凍空調工程系<br>107<br>The purpose of this study was to study on energy performance of Magnetic Bearing Centrifugal Chiller Applied in Factory Buildings. Given that there were more manufacturers producing this kind of chillers and emphasizing the higher efficiency and energy saving rate, it did a 24-hours observation and collected data at it’s peak load and general load in order to verify the statement above and anticipate more general use of these chillers in office buildings and factories in the near furture.
The research was based on the air conditioning system in the certain office building.We collected and recorded related data through its central supervisory and remote control system day by day. By analyzing and making cross comparison of the data in operating period (Evaportor Leaving Water Temperature is set at 7 to 10 degrees Celsius.),we came to the conclusion that when adjusting the evaporator leaving water temperature to a higher degree，not only lowers down the loading rate of Magnetic Bearing Centrifugal Chiller in operation,but enhances the data-bases of the following items like the chilled water temperature difference,cooling water temperature difference, input power consumption of the compressor,coefficient of performance(C. O. P),power consumption of each Refrigeration Ton(kW/RT)，intake and exhaust pressure ratio of the system(PHP/PLP).The result showed that the energy efficiency is considerable when operating the Magnetic Bearing Centrifugal Chiller in its partial load.
Due to the fact that the performance and energy saving efficiency of the frequency magnetic centrifugal chiller was not fully studied and revealed to the air conditioning industry, we expected the result of this research to have a certain reference value in choosing this chiller as the first priority considering its energy saving effect
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Yen, Kuang-Ting, and 顏光廷. "Energy Savings of a Variable Speed Drive Retrofit for a Fixed Speed Centrifugal Chiller." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/2v3j2e.
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碩士<br>國立臺北科技大學<br>冷凍與低溫科技研究所<br>102<br>Variable Speed Drive is wide application in air-conditioner industrial. It is one of the major device for energy saving strategy. Recenly, Variable Speed Drive is fully developed. The high capacity Variable Speed Drive becomes more popular because lower price and performance are improved.
The research case used energy management system to record data in order to analysis running data when applying variable speed drive retrofit for a fixed speed centrifugal chiller. The measured data include chiller energy consumption, inter-guide-vane open percentage, frequency of speed, entering and leaving water temperature of the condenser, entering and leaving water temperature of the evaoprator, and efficiency of chiller. This reseach used computer software“Chiller System optimizer”to estimate the chiller energy consumption in Taipei climate, then analyzed the relationship between all of the collected data.
To sum up this research of variable speed drive retrofit for a fixed speed centrifugal chiller, the simulation software estimates the total annual energy saving is 14.5% in this case. The actual annual energy consumption saving was 34.9%, and the highest saving ratio happened in January.
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WANG, HSIAO-WEN, and 王筱雯. "Application of GBDT and FCBF on the Fault Detection and Diagnosis of Centrifugal Chiller." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/4k9nm9.
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碩士<br>國立臺北科技大學<br>能源與冷凍空調工程系<br>107<br>In this research, Data mining is applied to the fault diagnosis of Centrifugal Chiller. Then verify the research method through ASHRAE RP-1043[1] Centrifugal Chiller operational data, and make effective data classification by data mining. When the R software is applied for data mining, to imporve classification efficieny of large data amount and multiple variables, Dimension Reduction is applied to data before data analysis. Therefore, the Fast Correlation Based Filter for Feature Selection（FCBF） is used in this research to retrieve optimal feature subset, and develop Fault Detection and Diagnosis（FDD） of Centrifugal Chiller by Gradient Boosting Decision Tree（GBDT） to undertake the Fault Detection and Diagnosis of seven common Centrifugal Chiller faults. The results show that the diagnostic rate using the Fast Correlation Based Filter for Feature Selection（FCBF） combined with the Gradient Boosting Decision Tree （GBDT) is 20.89% higher than the Linear Discriminant Analysis（LDA） combined with the Support Vector Machine（SVM）.
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Yang, Wen-lang, and 楊文郎. "Energy-saving Investigation though Applying Inverter-drive Centrifugal Chiller in a Car Spraying Manufacturing Factory." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/7kvpfx.
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碩士<br>國立勤益科技大學<br>冷凍空調系<br>106<br>Analysis and discussion about chiller system replacement and energy saving of a car factory in Taiwan is studied. Because of early-constructed spraying method that used cold water loop for main air conditioning system was not efficient, without automatic control for the system. It wasted large amount of energy and results in huge operating cost. In order to meet the energy conservation requirements of government and to improve the air conditioning system simultaneously, energy-efficient chillers with VPF (Variable Primary Flow) system was conducted accordingly. Control network improvement with real-time monitoring system which acquires data from operating equipment has been incorporated. Energy consumption and operating performance has been compared with the chillers before retrofitting. It will improve real-time monitoring system to determine the most stable and cost-effective method for operation. The results show that comparing to 2015, natural gas saving is NTD 6,262,000 cooling tower saving about NTD 161,280 and CO2 emission reduction is about 517 tons in 2016. This study presents the most economical and energy-efficient example for retrofitting absorption chiller by applying energy efficient centrifugal chillers.
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CHEN, YAO-PIN, and 陳耀斌. "A study on TAB and Energy Conservation of the Centrifugal Magnetic Suspension Water Chiller Unit." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/wfa25n.
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碩士<br>國立勤益科技大學<br>冷凍空調與能源系<br>107<br>As global warming becomes more and more serious, mitigating global warming and reducing carbon dioxide emissions for the next generation have been everyone’s responsibility. In order to responded to this and reduce global warming, and lower carbon dioxide emissions, the Executive Yuan of Taiwan promoted the policy of energy conservation and carbon emission reduction. For this purpose, the energy conservation and carbon emission reduction promotion committee was established and the green smart building system was researched and developed. The energy consumed by buildings accounts for 40% of the main energy consumed in the country. There is a construction quality management system before building design and construction, under construction, and after construction completion and acceptance.
Therefore, in this study, a 150RT water chiller unit of the central air-conditioning was replaced and updated to a 240RT variable frequency centrifugal magnetic suspension water chiller unit with a cooling water pump and a chilled water pump, and a variable frequency system of the variable primary flow chilled water system was imported, to detect the temperature at the end of the chilled water pipes and the differential pressure control technology, and to adjust operational state of the load side water supply pump to be the best. A variable frequency unit and a variable frequency system were matched with chilled water temperature and flow management, to reduce the operating cost of air-conditioning and to establish the building energy management system. The high-efficiency unit was updated and the monitoring management system of the “building energy management system” was upgraded, to gain the operational states of all unit devices, the change data during the regulation process and the energy conservation benefits of the unit frequency control, so as to facilitate detailed records of operation data for analyzing the reasons.
In this study, throughout the year, 1.54% of the refrigerating capacity, 39.2% of the power consumption (kW), 25.3% of the electric energy consumption (kWh/y), 25.3% of the electric charge, 4.88 return years and 25.3% of the electric energy consumption (kWh/y) for carbon emissions were saved. This study can actually achieve the goal of energy conservation benefits, reduce the impacts on environment, create high quality medical environment and protect the environment to promote sustainable development.
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Shih, Po-Wei, and 施博偉. "Study on Power Consumption of Centrifugal Chiller Caused by Variation of Inlet Guide Vane and Diffuser." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/g6q9v6.
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碩士<br>國立臺北科技大學<br>能源與冷凍空調工程系碩士班<br>105<br>Ever since a long time Building energy saving issues have been discussed. Electricity consumption comparison in the building equipment, the largest HVAC system power consumption. In HVAC system, chiller has been largely applied in office buildings, schools, hospitals and industrial system for cooling. This thesis that variation of inlet guide vane and diffuser open percentage on power consumption of chiller. The building is under study in Taipei city. Variation of inlet guide vane and diffuser opening percentage in different cooling water inlet temperature, use of PCDCT software records for data analysis. It was found that correctly cooling water temperature could increase efficiency of chiller with different average line current. In addition, it was found that change-opening percentage of diffuser was positively correlated with kW/RT; and further, diffuser was maintained 30% or less to achieve the power consumption of 0.6 kW/RT. This is Chiller for the best operating performance. It can be seen caused by cooling water inlet temperature and opening percentage variation of diffuser.
It is expected that by using this thesis, variation of inlet guide vane and diffuser of centrifugal chiller can provide HVAC engineer understand monitoring program logic of the ancillary equipment in the design of HVAC system and Programmable Logic Controller.
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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<br>國立臺北科技大學<br>冷凍與低溫科技研究所<br>92<br>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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Chen, Kuan-Min, and 陳冠銘. "R-123 Centrifugal Chiller’s refrigerant leakage study." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/32py3r.
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碩士<br>國立臺北科技大學<br>能源與冷凍空調工程系碩士班<br>101<br>The environmental friendly, low-energy consumption and high-efficiency negative pressure centrifugal chiller is the primary choice of air conditioners currently. But the leakage of the refrigerant of the negative pressure centrifugal chiller is one of the major reasons causing damages to the centrifugal chiller component. Therefore, to increase the lifetime life and reduce the probability of malfunction and leakage is an important topic. Since short of the operational and maintenance personnel who truly understand and familiar with the negative pressure centrifugal chiller, abnormity and leakage are often caused by human errors. This thesis focused on the analysis of the leakage position of the negative pressure centrifugal chillers by using 15 years of on-site practical experience and system failures. And to conduct a systematic analysis by the rule of thumb and leakage position analysis according to the relevant operation leakage status under the long-term maintained environment. So that it can provide a maintenance basis for reference and comparison of empirical data to those who are interested in and currently engaged in large-scale air-conditioning chiller maintenance occupation. Furthermore, a systematic comparison and tracking on the centrifugal refrigeration and air conditioning systems are performed and the positions of the leakage then under different circumstances are summarized. Base on this study, we found that, conducting quarterly tracking and preventing detection on the easily leaked positions, improving the joint sealing materials, implementing annual vibration analysis measurements, will help to greatly improve the stability of the negative pressure centrifugal chillers.
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WANG, CHUNG-WEI, and 王忠維. "Benefit Analysis of Magnetic Bearing Centrifugal Chillers series Water Source Heat Pump." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/w2j29u.
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碩士<br>國立臺北科技大學<br>能源與冷凍空調工程系<br>107<br>This research is mainly used for the mixing of heat pump and ice water during the operation of maglev. Since the maglev has better integrated part load value (IPLV), it can obtain higher ice water efficiency under partial load. The heat pump has a higher heat transfer efficiency, and the energy transfer process requires only a small portion of the power to provide a better amount of hot water heating.
In the case of this study, the improved efficiency of the maglev host can reach an average of about 28% to 30% energy saving. After the hot water is improved, the heat pump has a 14.42% energy saving effect on the steam, which has quite significant effects. In this study, the energy efficiency analysis of the ice water host is carried out for the cold source provided by the heat pump on the ice water supply end. After the power consumption model is established by regression analysis, the data of the heat pump is supplied to verify that the heat pump supplies the cold source. The efficiency of the ice water host is improved.
The results show that after verifying under the same conditions, it is found that the heat pump has the effect of saving electricity for the ice water main unit, and the data saving rate under the same conditions calculated in the case is 4.78%, which shows that when the heat pump is from When the ice water is returned to the water to take heat, the ice water host has energy saving benefits.
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Chen, Chun-Hung, and 陳俊宏. "Study of an Automated Fault Detection and Diagnosis (FDD) Strategy for Centrifugal Chillers." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/36wuev.
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碩士<br>國立臺北科技大學<br>能源與冷凍空調工程系碩士班<br>96<br>There are two kinds of centrifugal chiller faults, “Hard faults”and“Soft faults”. Soft faults means system operating process and unsuitable maintaining cause low performance fault, it is usually hard to find in the early stage. The fault can’t be detected and promulgated immediately, effecting the automatic control and performance monitor normal operation, causing large energy consumption. In order to raise the operating stability of centrifugal chiller in a long term, studying on an Automated Fault Detection and Diagnosis (FDD) Strategy research appears very important.
The present paper studied on developing innovative Automated Fault Detection and Diagnosis (FDD) Strategy with centrifugal chiller. First, finding representative performance index regression model for Automated FDD Strategy from references and analyzing and estimating with experiment data. Second, by the experiment on the fault of centrifugal chiller, analyzing this paper and other references with chart and quantize the innovative Automated FDD Strategy with all kinds of faults in Fault detection rate and Fault Diagnosis rate.
The result revealed that only multivariate polynomial regression model eleven performance indexes are in 5% of CVRMSE standard. Four models have the best anticipative ability in eleven performance indexes. Otherwise, Wang’s fault classifier can only diagnose three kinds of faults and Reddy’s is four, but this paper is seven. Finally, when the fault degree reaches four, both the fault detection rate and the fault diagnosis rate are between 67~100%.
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Chen, Ming-Ke, and 陳明科. "Energy Efficiency of Centrifugal Chillers under Different Heat Loads and Cooling Water Temperatures." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/29268326233620966979.
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碩士<br>國立勤益科技大學<br>冷凍空調系<br>101<br>In this study, centrifugal chillers of 1000 USRT with constant and varied speed in Chiayi area of Taiwan was investigated, respectively, in order to understand their operation efficiencies under different heat loads and different cooling temperatures. Through the simulation of the software, YORKWORK, it is found that the performance of the chiller with constant speed is superior to that of the chiller with varied speed while the operation condition is 100% heat load and the temperature of cooling water is above 27 ℃ or the operation condition is 90% heat load and the cooling temperature is above 30℃. From the simulation, it is also indicated that 4.7% efficiency difference between the two chillers can be reached under the operation conditions mentioned above. Except the operation conditions mentioned above, the performance of the chiller with varied speed is greater than that of the chiller with constant, the maximum efficiency difference of 40.46% can be obtained. Furthermore, from the experimental results, it is also shown that while the operation condition is above 80% heat load and cooling temperature is above 29℃, the efficiency of the chiller with constant frequency is 6.2% superior to that of the chiller with varied frequency. Except the operation condition mentioned above, the performance of the chiller with varied speed is always greater than that of the chiller with constant, the maximum efficiency difference of 49.8% can be obtained in experiments. From the measured energy consumption of individual constant and varied speed chillers,an optimum operation strategy for the HVAC system in a hospital of chiayi was developed. While the heat load of the system is higher and the ambient dry bulb temperature is opened to operate in full load condition as possible. While the heat load is lower and the ambient dry bulb temperature is under 29℃, the system tempt to open the varied speed chiller and shutdown the constant speed chiller. Through the optimum operation, the enery consumption of the system within a year is the lowest in comparison to the of the system operating under fully constant speed chillers or fully varied speed chillers.
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CHEN, WEI-CHUNG, and 陳緯中. "The Operation Efficiency Analysis of Varied Frequency Centrifugal Chillers in the Climate Conditions of Taiwan." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/41365489807242291735.
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博士<br>國立勤益科技大學<br>冷凍空調系<br>99<br>This study respectively simulated the operation efficiencies of constant and varied frequency centrifugal chillers with the same refrigerant capacity under the influence of different part load conditions and different inlet temperatures of cooling waters according to the climate conditions in Taiwan. The simulated results reveal that the operation of the varied frequency chiller can reach better efficiencies under the conditions of lower inlet temperature of the cooling water and part load operation. In comparison with the constant frequency chiller, while the inlet cooling water is 18℃ and full load operation, 12% energy saving can be reached for the varied frequency chiller. While the inlet cooling water is also 18℃ and the chillers operation under 75% and 50% part loads, the 24% and 31% energy saving effect can be reached respectively in the simulation. The results can be useful references for the HVAC designer for considering the chiller operation conditions and the environmental climate conditions on the chiller efficiency in order to reach a suitable operation conditions and the goal of energy saving.
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CHENG, CHIH-MING, and 鄭智銘. "A Case Study: The Application of Two-Stage Variable Frequency Centrifugal Chillers in A Medical Center." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/773dqk.
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碩士<br>國立臺北科技大學<br>能源與冷凍空調工程系<br>107<br>Location: Taiwan - Taipei City, Building Use: Medical Center (5185 people), Area Range: Floor area of 364,500 square meters, Air-conditioning area: 325,700 square meters, There are 9 units of 9520RT Because the original system is all fixed-frequency centrifuge chiller, the low-load efficiency is relatively poor. In this study, we replaced three centrifuge chiller such as R-3&R-4 total two 1500RT (efficiency 0.65kW/RT) and R-8 one 800RT (efficiency 0.83kW/RT). 800RT chiller original The centrifuge chiller for ice storage has been scrapped and disabled. Two 1500 RT centrifuge chiller have been installed for 28 years. The performance is low and the old-fashioned replacement limit has been reached. Therefore, this study will be replaced. The frequency conversion centrifuge is better than the fixed-frequency centrifuges energy consumption of about 35% for the component load, Centrifuge Chille R-3, R-4 and R-8 optional 19XRE frequency conversion centrifuge 1200RT. Using R-134a environmental protection refrigerant, high efficiency two-stage variable frequency centrifugal chillers 0.551 kW / RT, the efficiency is better than the 2005 chiller performance of the Republic of China announced 0.576kW / RT. As for the Integrated Part Load Value (IPLV), the efficiency of the three chillers operating at the input sy3tem compared to the new standard of ASHRAE STD 90.1 2015 is 0.333 kW / RT, which is better than the new ASHRAE standard of 0.38 kW / RT. Therefore, the efficiency of the glazing unit R-3, R-4 and R-8 is better than that of the centrifuge chiller control group established in this case. In this study, three frequency conversion centrifuge chiller were replaced. According to the statistical results of measurement, the system efficiency was greatly improved from the existing COP 3.58 to COP 5.02, and the system efficiency can be operated between COP 4.0 and 5.9±5%.
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Chiang, Chang-Hsueh, and 江長學. "Development of Fault Detection and Diagnosis Strategy Using Fuzzy Inference and Neural Network Theories for Centrifugal Liquid Chillers." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/8ucgku.
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碩士<br>國立臺北科技大學<br>冷凍空調工程系所<br>98<br>Aim of this research is using theories of fuzzy inference and neural network to develop fault detection and diagnosis (FDD) strategy for centrifugal chiller. And explore to influence of fault diagnosis rate and misdiagnosis rate in different fault diagnosis strategy to find more suitable fault detection and diagnosis strategy for centrifugal chiller. For seven soft fault of centrifugal chiller, fault diagnosis rate and misdiagnosis rate of fuzzy inference FDD strategy were 88.0% and 12.0%; fault diagnosis rate and misdiagnosis rate of neural network FDD strategy were 93.7% and 6.3%. Compared with Chen [11] FDD strategy (34.8% and 65.2%), raised diagnosis rate and reduced misdiagnosis rate. For six soft fault of centrifugal chiller, fault diagnosis rate and misdiagnosis rate of fuzzy inference FDD strategy were 97.2% and 2.8%; fault diagnosis rate and misdiagnosis rate of neural network FDD strategy were 98.5% and 1.5%. Compare with Lin [12] FDD strategy (36.4% and 53.6%), raised diagnosis rate and reduced misdiagnosis rate.FDD strategy using fuzzy inference and neural network both could raised diagnosis rate and reduced misdiagnosis rate. Compared the two strategy, neural network is better. Therefore, fault detection and diagnosis strategy using neural network is most suitable strategy for centrifugal chiller.
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Ling, Shih-Kang, and 凌士剛. "Study of the Influence of Predicting Accuracy of Performance-Index Regression Models on Fault Detection and Diagnosis Strategy for Centrifugal Chillers." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/49af97.
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碩士<br>國立臺北科技大學<br>能源與冷凍空調工程系碩士班<br>97<br>This research mainly explores the influence of predicting accuracy of performance-index regression models on fault detection and diagnosis rate, so as to get the best performance-index regression models for developing centrifugal chiller FDD strategy. First, use the experimental data─five centrifugal chiller regression models, to make an overall evaluation of eleven performance indices’ predicting accuracy. And then apply the six soft- fault experimental data into five performance-index regression models to analyze Fault detection and diagnosis rate.
The result shows that MP and FEMP model have the best predicting accuracy in performance indices as well as fault detection-and-diagnosis rate, with CVRMSE 2.03% and the average rate of fault detection and diagnosis reaching up to 96.91%. It indicates that performance-index regression models with higher predicting accuracy can do better at Fault detection and diagnosis rate. The calculative procedure of FEMP model is much more complicated than MP Model so it is the most suitable performance-index regression model for developing the centrifugal chiller FDD strategy.