Gotowe bibliografie tematyczne / Centrifugal chiller

Gotowa bibliografia na temat „Centrifugal chiller”

Autor: Grafiati

Data publikacji: 4 czerwca 2021

Data aktualizacji: 1 lutego 2022

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Artykuły w czasopismach na temat "Centrifugal chiller"

Cappenberg, Audri Deacy. "Analisis Chiller Dengan Menggunaan R123 Dan R134a Pada Kinerja Pendinginan". JURNAL KAJIAN TEKNIK MESIN 5, nr 1 (13.04.2020): 48–57. http://dx.doi.org/10.52447/jktm.v5i1.3979.

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AbstrakChiller adalah mesin refrigerasi yang memiliki fungsi utama mendinginkan air pada sisi evaporator, air yang didinginkan selanjutnya didistribusi ke alat penukar kalor (FCU; fan coil unit). Chiller sudah menjadi pilihan dalam pengkondisian udara ruangan dalam skala besar maupun dalam mesin-mesin proses. Penelitian ini bertujuan untuk mengetahui kinerja pendingin chiller centrifugal water cooled (dari beberapa jenis chiller yang tersedia) yang berkapasitas relatif besar, dengan menggunakan refrigeran R-123 dan R-134a sebagai media pendingin. Dari hasil penelitian dan pengolahan data maka untuk chiller yang menggunakan R-123 didapatkan COP = 2.68; GWP = 76; emisi ; CO2= 43.324.512,58 kg; ODP = 0.02 dan untuk chiller yang menggunakan R-134a didapatkan : COP = 5.74; GWP = 1300; emisi ; CO2= 47.953.644 kg; ODP = 0.0. Kata kunci: Chiller centrifugal water cooled, R123,R134a,COP,ODP dan GWP AbstractChiller is a refrigeration machine that has the main function of cooling the air on the evaporator, the cooled air is then distributed to the heat exchanger (FCU; fan coil unit). Chiller has become the choice in room air conditioning on a large scale as well as in process machines. This study aims to determine the performance of centrifugal chiller water cooled chillers (from several types of chillers available) with relatively large capacities, using R-123 and R-134a refrigerants as cooling media. From the results of research and data processing, the chiller using R-123 obtained COP = 2.68; GWP = 76; emissions; CO2 = 43,324,512.58 kg; ODP = 0.02 and for chillers using R-134a obtained: COP = 5.74; GWP = 1300; emissions; CO2 = 47,953,644 kg; ODP = 0.0. Keywords: Chiller centrifugal water cooled, R123,R134a,COP,ODP dan GWP

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Hsu, Chih-Neng, i Shih-Hao Wang. "Evaluating the Performance of Water Chillers Equipped with Constant- or Variable-Frequency Centrifugal Compressors". Processes 9, nr 6 (14.06.2021): 1039. http://dx.doi.org/10.3390/pr9061039.

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The cooling coefficient of performance (COPR) and energy efficiency ratio (EER) of refrigerant R-134a compressors (single- and double-compressors) with different refrigerant tonnage (200, 250, 300, 380, 500, and 700 RT) for centrifugal and Maglev centrifugal compressors change with different operating performance load percentages (10–100%), and constant-frequency and variable-frequency operation, resulting in performance differences. In particular, a water chiller can have a fixed cooling water inlet temperature of 32 °C and a variable cooling water inlet temperature between 18.33 °C and 32 °C. According to the actual test results, the commercial performance code program and parameter table of the water chiller were established. Based on the performance matching of different load chillers, the on-site load capacity was analyzed and the effective water chiller performance and model matching were determined as the best choice for the tonR number of the deicing machine and unit matching, providing a reference for a future large water chiller that cannot be used on site for a single unit tonR. To achieve energy-saving benefits, different types of compressors, different refrigeration tonR operation, constant-frequency unit and variable-frequency unit alternate operation, and different operating performance load percentage operation can be allocated. Finally, the results show that, when the cooling water inlet temperature is fixed, the Maglev variable-frequency centrifugal compressor water chiller is better than the constant-frequency centrifugal water chiller, and also better than the variable-frequency centrifugal water chiller. The larger the freezing tonR of the variable-frequency centrifugal water chiller, the smaller the difference between COPR and EER. When the cooling water inlet temperature changes, the Maglev variable-frequency centrifugal water chiller is better than the constant-frequency centrifugal water chiller, and it is also better than the variable-frequency centrifugal water chiller. The larger the freezing tonR of the variable-frequency centrifugal water chiller, the smaller the difference between COPR and EER. Moreover, the operating performance of the constant-frequency centrifugal water chiller is between 60% and 90%, which can maintain relatively high COPR and EER values. The operating performance of the variable-frequency centrifugal water chiller is between 40% and 70%, which can maintain relatively high COPR and EER values. Compared with the constant-frequency and variable-frequency, the Maglev variable-frequency centrifugal water chiller can maintain higher COPR and EER values when the operating performance is between 10% and 100%. When the operating performance is between 10% and 70%, it can maintain very high COPR and EER values. When the water chiller is selected in the field, the energy-saving of COPR and EER will be given priority. Therefore, the load capacity can be used to effectively manage the water chiller performance and model selection, so that the operation performance can reach the best percentage and energy saving can be achieved.

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SATHTHASIVAM, JAYAPRAKASH, GARY TANG i KIM CHOON NG. "EVALUATION OF THE SIMPLE THERMODYNAMIC MODEL (GORDON AND NG UNIVERSAL CHILLER MODEL) AS A FAULT DETECTION AND DIAGNOSIS TOOL FOR ON-SITE CENTRIFUGAL CHILLERS". International Journal of Air-Conditioning and Refrigeration 18, nr 01 (marzec 2010): 55–60. http://dx.doi.org/10.1142/s2010132510000071.

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The application of Fault Detection and Diagnosis (FDD) could play a key role in operating chillers at optimum efficiency. As air-conditioning consumes a significant proportion (approximately 30% to 50%) of the total power consumption of a commercial building, an effective FDD tool is very much required for a reliable and economic chiller operation. In this paper, the renowned Simple Thermodynamic Model, STM (also known as Gordon and Ng Universal Chiller Model) was utilized to detect and diagnose some of the common faults in centrifugal chillers. Based on the readily available, nonintrusive, steady state measurements extracted from the on-site chillers, the STM model was regressed to obtain two physically meaningful coefficients, namely, Thermal Resistance and Internal Entropy Generation. These information-rich coefficients were then analyzed to evaluate the performances and the conditions of the chillers. Despite the large and yet complex on-site chiller operations, equipped with built-in heat recovery, such as economizer and intricate control mechanisms, the predictive and diagnostic capabilities of STM in detecting chiller faults has been successfully tested and evaluated based on the data collected from on-site centrifugal chillers. Faults like condenser fouling and reduction in condenser cooling water flow rate were succinctly captured by the STM model.

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Wang, Zhiyi, Jiachen Zhong i Zudong Pan. "Research of cooling load & chiller selection in metro station". International Journal of Low-Carbon Technologies 15, nr 4 (7.04.2020): 506–12. http://dx.doi.org/10.1093/ijlct/ctaa015.

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Abstract Air conditioning is of the most energy saving potential system in the metro station. This study analyzes the composition and characteristics of air conditioning cooling load in a metro station. The hourly distribution and the proportion of each cooling load are calculated. The results show that cooling load fluctuation of metro air conditioning is large, and the operating time of different load varies greatly. According to the air conditioning cooling load, the coefficient of performance of the fixed frequency screw, variable frequency screw, series countercurrent screw and magnetic bearing centrifugal chiller under the load of 20–100% are tested. The annual operating cost of four chillers is compared. Test results show that the magnetic bearing centrifugal chiller has a much higher coefficient of performance at part load and lower annual operating cost. Increased initial investment can be recovered in less than 2 years. The magnetic bearing centrifugal chiller is suitable as a cold source of air conditioning system in the metro station.

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Jia, Yongzhong, i T. Agami Reddy. "A Model-Based Feed-Forward Controller Scheme for Accurate Chilled Water Temperature Control of Inlet Guide Vane Centrifugal Chillers". Journal of Solar Energy Engineering 127, nr 1 (1.02.2005): 47–52. http://dx.doi.org/10.1115/1.1775225.

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Capacity control in most commercial centrifugal chillers is achieved by inlet guide vanes which are activated by the leaving chilled water temperature sensor. Due to mechanical reasons, vane control is done discretely, and not continuously. The control module compares the value provided by the temperature sensor to pre-set control band values, and if those bands are exceeded, it sends a signal to the vane control motor to adjust the vane position by one step which could be upwards or downwards. The advantage of this type of discrete control method is its simplicity. Normally, the accuracy in the outlet chilled water temperature is of the order of 0.5°C, which is acceptable for normal cooling plants such as used in office buildings. However, there are applications such as in pharmaceutical processes, mechanics labs, or instances in chemical processes where more accurate control is required (sometimes as low as 0.05°C). This paper proposes a simple method to achieve such tight control without any hardware modifications. The basis of this method is a transient physical inverse model of the refrigerant boiling process in the evaporator, in conjunction with a feed-forward control scheme. The model parameters need to be identified from monitored data since they are chiller-specific. This paper describes the model, and applies it to one-minute monitored data from an actual chiller plant of 1580 kW (450 Tons). It is demonstrated that for this specific chiller such a control scheme has the potential to improve control accuracy by about 28% as compared to the traditional control method.

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Zamhuri, Muhammad Ikhwan, Haslenda Hashim i Ho Wai Shin. "Optimal Design of Integrated Chiller Capacity with Ice Thermal Storage for Commercial Buildings through Cooling System Cascade Analysis". International Journal of Innovative Technology and Exploring Engineering 10, nr 2 (10.12.2020): 165–75. http://dx.doi.org/10.35940/ijitee.b8301.1210220.

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Chilled water air conditioning system is used to supply cooling systems in large capacity for industrial processes and commercial buildings. Air conditioners contribute more than 60 percent of electricity consumption in buildings. District Cooling System (DCS) technology comprises a central chiller plant which provides advantage compared to local air conditioning system. It has higher efficiency, uses less power in system operation, allows more usable space in buildings, and can be operated with minimum manpower while handling same amount of cooling load. The integration of a chiller with ice thermal storage (ITS) offers more operational flexibility while reducing space cooling expenses. This paper presents a systematic framework for design and operation of District Cooling Plant (DCP) comprising an integrated chiller and ice thermal storage system. The Cooling System Cascade Analysis (COSCA) based on pinch analysis is constructed to determine the chiller optimal size and ice thermal storage capacity. The District Cooling System configuration for this study comprises a cooling tower, chiller (centrifugal, variable centrifugal, glycol) and ice thermal storage system. The application of this technique to fulfil 66,284 refrigerant tonne hour (RTH) cooling load demand from commercial buildings reveals the optimal capacity of the chiller is 3068.91 refrigerant tonne (RT), ice tank rating at 989 refrigerant tonne (RT) and ice tank capacity is 9892.75 refrigerant tonne hour (RTH).

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Hwang, YoonJei, HanYoung Park, SaiKee Oh, HoRim Lee, YoungSu Park i KamGyu Lee. "The evaluation of energy saving performance for the modular design centrifugal chiller". E3S Web of Conferences 111 (2019): 01018. http://dx.doi.org/10.1051/e3sconf/201911101018.

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The modular concept design and operation of a centrifugal chiller offers the potential of increased cycle efficiency both at full load and off load conditions compared to the single compressor chiller. Modular chiller design is that a smaller, individual chiller can be connected with another, to make a larger capacity system. In the case of a tandem chiller, there would be faced to the higher initial cost or bigger foot print than a single compressor chiller at the same capacity because manufacturing cost, weight and size will be decreased according to increase of the refrigeration capacity. Therefore, it is obvious that a modular chiller have to be improved its efficiency first by both the operation algorithm and major cycle components. Eventually, the efficiency of the modular chiller achieves up to 6% at the full load condition after added series counter flow effect as much as 3% and more 3% added by improved aerodynamic design for impeller. Moreover, maximize off design potential through the capacity combination algorithm as the way of uneven loading makes 24% improved based on AHRI 550/590.

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Ng, K. C., T. Y. Bong i H. T. Chua. "Performance Evaluation of Centrifugal Chillers in an Air-Conditioning Plant with The Building Automation System (BAS)". Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 208, nr 4 (listopad 1994): 249–55. http://dx.doi.org/10.1243/pime_proc_1994_208_045_02.

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A thermodynamic model with a novel method of describing the performances of centrifugal chillers for air-conditioning is presented. It is based on the first and second laws of thermodynamics which captures the overall entropy change due to non-isentropic compression and expansion of the thermodynamic cycle. The model gives the fundamental relation between the coefficient of performance (COP) and the cooling rates (Qe) for (a) the modulating and (b) the throttling actions of the inlet guide-vanes of the compressor. The usefulness and the accuracy of the model are demonstrated here by analysing the in situ performance of two commercial, installed centrifugal chillers of an air-conditioning plant as well as comparing the available performance data of another chiller in the literature.

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Jia, Yongzhong, i T. Agami Reddy. "Characteristic Physical Parameter Approach to Modeling Chillers Suitable for Fault Detection, Diagnosis, and Evaluation". Journal of Solar Energy Engineering 125, nr 3 (1.08.2003): 258–65. http://dx.doi.org/10.1115/1.1567317.

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Model-based fault detection and diagnosis approaches based on statistical models for fault-free performance concurrently require a fault classifier database for diagnosis. On the other hand, a model with physical parameters would directly provide such diagnostic ability. In this paper, we propose a generic model development approach, called the characteristic parameter approach, which is suitable for large engineering systems that usually come equipped with numerous sensors. Such an approach is applied to large centrifugal chillers, which are generally the single most expensive piece of equipment in heating, ventilating, air-conditioning, and refrigeration systems. The basis of the characteristic parameter approach is to quantify the performance of each and every primary component of the chiller (the electrical motor, the compressor, the condenser heat exchanger, the evaporator heat exchanger, and the expansion device) by one or two performance parameters, the variation in magnitude of which is indicative of the health of that component. A hybrid inverse model is set up based on the theoretical standard refrigeration cycle in conjunction with statistically identified component models that correct for non-standard behavior of the characteristic parameters of the particular chiller. Such an approach has the advantage of using few physically meaningful parameters (as against using the numerous sensor data directly), which simplifies the detection phase while directly providing the needed diagnostic ability. Another advantage to this generic approach is that the identification of the correction models is simple and robust, since it requires regression rather than calibration. The entire methodology has been illustrated with actual monitored data from two centrifugal chillers (one a laboratory chiller and the other a field operated chiller). The sensitivity of this approach to sensor noise has also been investigated.

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Huang, Xinghua, Yunqian Zhang, Zuqiang Li i Yaolin Lin. "Measurement Method and Experimental Analysis of Liquid Entrainment for a Flooded Evaporator of a Water-Cooled Centrifugal Chiller Based on Energy Balance". Applied Sciences 11, nr 17 (2.09.2021): 8165. http://dx.doi.org/10.3390/app11178165.

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Liquid entrainment in a flooded evaporator has an important impact on the performance and safety of a water-cooled centrifugal chiller. In this paper, two methods for measuring the liquid entrainment factor in the evaporator of a centrifugal chiller based on energy balance are proposed. Method 1 involves only the heat exchange capacity of the evaporator and Method 2 involves both evaporator and condenser. The applicable conditions of the methods are discussed. Experimental measurements on the flooded evaporator of a single-stage water-cooled centrifugal chiller with refrigerant R134a show that, for a system with good thermal balance, there is little difference in the entrainment factor values obtained by the two methods. Method 2 was found to have slightly higher measurement accuracy, compared to Method 1. The uncertainty propagation analysis shows that for Method 2, the inlet and outlet water temperatures of the evaporator and condenser, motor input power, motor efficiency, transmission power loss and compressor suction and discharge temperatures are important factors. The experimental results show that the variation of the evaporator entrainment factor with refrigerant charge amount is different for different cooling capacity. At 700 and 800 refrigeration ton (RT), the entrainment factor of the test evaporator increases with the increase of refrigerant charge and the growth rate gradually accelerates. For the chiller tested, when the entrainment factor reaches 0.89% and 1.02%, respectively, at 700 ton and 800 ton, the rapid increase of the entrainment factor leads to a significant decrease in the coefficient of performance (COP) during the charging process. Based on the analysis of the experimental results, it is recommended that the maximum entrainment factor for efficient operation of the centrifugal chiller should be controlled within 1%.

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Rozprawy doktorskie na temat "Centrifugal chiller"

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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Submitted by Rafael Santana (rafael.silvasantana@ufpe.br) on 2017-07-12T17:40:35Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese_Gutenberg da Silva Pereira_1.pdf: 6410667 bytes, checksum: ddf1e84a9a1b8bcce71836f13e8707fa (MD5)
Made available in DSpace on 2017-07-12T17:40:35Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese_Gutenberg da Silva Pereira_1.pdf: 6410667 bytes, checksum: ddf1e84a9a1b8bcce71836f13e8707fa (MD5) Previous issue date: 2016-02-22
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.
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
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, i 王文瑞. "Economic Validation of VFD Centrifugal Chiller". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/z6c66y.

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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
100
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, i 劉青龍. "Economic Analysis of VFD Centrifugal Chiller". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/kcezqh.

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碩士
國立臺北科技大學
冷凍空調工程系所
93
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
國立臺北科技大學
冷凍與低溫科技研究所
90
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, i 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
國立臺北科技大學
能源與冷凍空調工程系碩士班
101
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, i 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
國立臺北科技大學
能源與冷凍空調工程系碩士班
104
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, i 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, i 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
國立臺北科技大學
能源與冷凍空調工程系碩士班
105
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, i 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
國立中央大學
機械工程研究所碩士在職專班
94
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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Części książek na temat "Centrifugal chiller"

Tudoroiu, Roxana-Elena, Mohammed Zaheeruddin, Sorin Mihai Radu, Dumitru Dan Burdescu i Nicolae Tudoroiu. "The Implementation and the Design of a Hybriddigital PI Control Strategy Based on MISO Adaptive Neural Network Fuzzy Inference System Models–A MIMO Centrifugal Chiller Case Study". W Learning and Analytics in Intelligent Systems, 215–35. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-49724-8_9.

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"minutes retention depending on the oil processed. Then, Synthetic silica hydrogels: Described in the immediately the oil is heated to 70°C, (158°F) to assist "breaking" the preceding section. emulsion and the mixture is passed through a primary (first) centrifuge. The general dosage of acid-activated bleaching earths is 0.3-0.6%, depending on the quality of the oil and bleach-In contrast, the short-mix process, developed in Europe, ing earth. Bleaching earths provide catalytic sites for de-is conducted at 90°C (84°F), uses a more highly concen-composition of oxidation products. Peroxide values (mea-trated caustic, and a mixing time and primary centrifuging sure of aldehydes) and p-anisidine values (precursors for time of less than 1 minute [135]. Less heat damage to the oxidative degradation) first rise and then decrease during oil and higher refining yield are claimed by advocates of bleaching. Bleaching processes used include atmospheric the long mix process. batch, vacuum batch, and continuous vacuum. Vacuum 4. Silica Absorption bleaching has the advantage of excluding air, partially by In traditional refining, oil from the primary centrifuge is vaporization of water in the earth, and is recommended. A washed with warm soft water to remove residual soap and typical vacuum bleaching process is 20-30 minimum at passed through a (secondary) centrifuge. The washed oil 100-110°C (212-230°F) and 50 mmHg absolute [135]. then is dried under vacuum. However, disposal of wash The reactions catalyzed during bleaching continue into water is increasingly becoming a problem, and the indus-the filter bed and are known as the "press bleaching ef-try is shifting to a modified caustic "waterless" refining fect." The reactive components of oil remain in the bleach-process. Soaps poison the adsorption sites of clays in later ing bed. Care should be taken to "blow" the filter press as bleaching operations and are removed by silica hydrogels. free of oil as possible and to wet the filter cake (which can The oil may be degummed with use of chelating acids, be very dusty) to prevent spontaneous combustion [137]. caustic neutralized, passed through a primary centrifuge, At this point, the product is RB ("refined, bleached") and may be partially vacuum-dried. Synthetic silica hy-oil. If the intended product is an oil, it can be sent to the de-drogels, effective in removing 7-25 times more phos-odorizer and become RBD. If solids are desired, the solids-phatides and soaps than clay on a solids basis, and for re-temperature profile of the oil may be modified by hydro-moving phosphorus and the major metal ions, is added genation, interesterification, or chill fractionation, alone or and mixed with the oil. By absorbing these contaminants in combination. first, the bleaching clay is spared for adsorbing chloro-6. Hydrogenation phyll and the oxidation-degradation products of oil Hydrogenation is the process of adding hydrogen to satu-[136-138]. rate carbon-to-carbon double bonds. It is used to raise try-5. Bleaching glyceride melting points and to increase stability as by jective of bleaching is to remove various contami-converting linolenic acid to linoleic in soybean oil [141]. A The ob lighter, "brush" hydrogenation is used for the latter pur-nants, pigments, metals, and oxidation products before the pose. oil is sent to the deodorizer. Removal of sulfur is especial-Most of the catalysts that assist hydrogenation are nick-ly important before hydrogenation of canola and rapeseed el-based, but a variety is available for special applications. oils. Flavor of the oil also is improved. As mentioned in the "Selectivity" refers to ability of the catalyst and process to preceding section, silica hydrogels will adsorb many of sequentially saturate fatty acids on the triglycerides in the these contaminants and spare the bleaching earth. Howev-order of most unsaturated to the fully saturated. For row er, earths are still used for these purposes in installations crop oils, perfect selectivity would be: that have not adopted hydrated silicas. Types of bleaching materials available include [136,139,140]: C18:3 C18:2 C18:1 Linolenic acid Linoleic acid Oleic acid Neutral earths: Basically hydrated aluminum silicates, sometimes called "natural clays" or "earths," and C18:0 fuller's earth, which vary in ability to absorb pigments. Stearic acid Acid-activated earths: Bentonites or montmorillonites, Although typical hydrogenation is not selective, it can be treated with hydrochloric or sulfuric acid to improve favored to a limited degree by selection of catalyst and by their absorption of pigments and other undesirable temperature and pressure of the process. Efficient hydro-components, are most commonly used. genation requires the cleanest possible feed stock (without Activated carbon: Expensive, more difficult to use, but of soaps, phosphatides, sulfur compounds, carbon monoxide, special interest for adsorbing polyaromatic hydrocar-nitrogen compounds, or oxygen-containing compounds) bons from coconut and fish oils. and the purest, driest hydrogen gas possible [140]." W Handbook of Cereal Science and Technology, Revised and Expanded, 361–73. CRC Press, 2000. http://dx.doi.org/10.1201/9781420027228-35.

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Streszczenia konferencji na temat "Centrifugal chiller"

Beghi, Alessandro, Luca Cecchinato, Marco Lissandrin i Mirco Rampazzo. "Oil-free centrifugal chiller optimal operation". W 2014 IEEE Conference on Control Applications (CCA). IEEE, 2014. http://dx.doi.org/10.1109/cca.2014.6981588.

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Yang, K. H., S. K. Lee, Y. S. Chiang, W. C. Chen i M. M. Ting. "A Comparative Study of Centrifugal Chiller Performances After CFC Refrigerant Conversion". W ASME 1997 Turbo Asia Conference. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/97-aa-037.

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Theoretical analysis indicated that, a typical centrifugal chiller could lose over 8% to 10% of its cooling capacity after converting from R-11 into using R-123 refrigerant. In this study, an attempt to recover some of this capacity loss by slightly decreasing its operating speed was analyzed. A full-scale experiment was performed to change the gear train of a 300 RT centrifugal chillier, which validated that 3%∼6% capacity recovery could be expected. This is a break-through to promote the chiller conversion for wide engineering applications and is discussed in detail in this paper.

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Jin, Guang-Yu, Xu-Dong Ding, Pek-Yew Tan i Tien-Ming Koh. "A hybrid water-cooled centrifugal chiller model". W 2011 6th IEEE Conference on Industrial Electronics and Applications (ICIEA). IEEE, 2011. http://dx.doi.org/10.1109/iciea.2011.5975975.

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Jia, Yongzhong, i T. Agami Reddy. "A Model-Based Feed-Forward Controller Scheme for Accurate Chilled Water Temperature Control of Inlet Guide Vane Centrifugal Chillers". W ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33343.

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Capacity control in most commercial centrifugal chillers is achieved by inlet guide vanes, which are activated by the leaving chilled water temperature sensor. Due to mechanical reasons, vane control is done discretely, and not continuously. The control module compares the value provided by the temperature sensor to pre-set control band values, and if those bands are exceeded, it sends a signal to the vane control motor to adjust the vane position by one step that could be upwards or downwards. The advantage of this type of discrete control method is its simplicity. Normally, the accuracy in the outlet chilled water temperature is of the order of 0.5°C, which is acceptable for normal cooling plants such as used in office buildings. However, there are applications such as in pharmaceutical processes, mechanics labs, or instances in chemical processes where more accurate control is required (sometimes as low as 0.05°C). This paper proposes a simple method to achieve such tight control without any hardware modifications. The basis of this method is a transient physical inverse model of the refrigerant boiling process in the evaporator, in conjunction with a feed-forward control scheme. The model parameters need to be identified from monitored data since they are chiller-specific. This paper describes the model, and applies it to one-minute monitored data from an actual chiller plant of 1580 kW (450 Tons). It is demonstrated that for this specific chiller such a control scheme has the potential to improve control accuracy by about 28% as compared to the traditional control method.

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Nayak, Sandeep, Erol Ozkirbas i Reinhard Radermacher. "Modeling of a 27 MW Combined Cycle Cogeneration Plant With Central Cooling Facility". W International Joint Power Generation Conference collocated with TurboExpo 2003. ASMEDC, 2003. http://dx.doi.org/10.1115/ijpgc2003-40161.

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This paper describes the modeling of a 27 MW combined cycle cogeneration plant with 10,000 tons chilled water central cooling facility. The cogeneration plant is designed to provide heating, cooling and electricity from a single fuel source viz., natural gas, though the gas turbines do have an inbuilt dual fuel combustion system. The topping cycle of the combined cycle cogeneration plant consists of two gas turbines each producing 11 MW of electric power at full load. The energy of the exhaust gases from these gas turbines is then utilized to generate steam in two heat recovery steam generators. The heat recovery steam generators are duct fired using natural gas to meet the peak steam load. In the bottoming part of the combined cycle, the steam from the heat recovery steam generators is expanded in a backpressure steam turbine to supply steam to the campus at about 963 kPa, generating an additional 5.5 MW of electric power in this process. There is no condenser wherein the campus acts as a sink for the steam. The central cooling facility is designed to supply 10,000 tons of chilled water out of which 3800 tons is supplied by two steam driven centrifugal chillers, which utilize a part of the steam supplied to the campus and the remaining by the centrifugal electric chillers. The combined cycle cogeneration plant along with the central chilled watercooling facility is modeled in a commercially available flexible cogeneration software package. The model is built based on the design data available from design manuals of gas turbines, heat recovery steam generators, backpressure steam turbine and centrifugal chillers. A parametric study is also done on the model to study the effect of different parameters like fuel flow rate, temperature etc on the output of the turbine and efficiency of the plant. Modeling of the inlet air-cooling of the gas turbine using an absorption chiller and electric chiller is also presented. Finally the paper discusses these results.

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Burandt, Bodo, i Matthias H. Buschmann. "New Centrifugal Compressor for Water Steam". W ASME Turbo Expo 2006: Power for Land, Sea, and Air. ASMEDC, 2006. http://dx.doi.org/10.1115/gt2006-90493.

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Environmental protection has been gaining more and more importance. Following this trend, the Institut fu¨r Luft- und Ka¨ltetechnik Dresden gGmbH (ILK) has designed a new chiller using water as natural refrigerant. Because of the special thermodynamic properties of water steam, the heart of the chiller, the centrifugal compressor, must be designed differently than the usual compressors used for refrigerating machines. This paper describes the compressor, its characteristic field and the test facilities used to investigate and optimize the compressor.

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Shaligram, Avinash G. "Solar Thermal Power for Large Chillers: A Feasibility Study". W ASME 2007 Energy Sustainability Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/es2007-36037.

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Centrifugal chillers using CFC’s were made in India in the capacity range from 150 TR to approximately 700 TR. Currently, there are around 500 units operating in India ranging in age from 10 to 30 years. All of these units will have to be replaced eventually since CFC’s are to be phased out by 2010 in Article 5 countries as per Montreal Protocol. The World Bank has made a detailed study of the issue and proposed a Global Chiller Replacement Project whereby the old units will be replaced by the current generation of energy-efficient chillers using non-CFC refrigerants. This paper deals with a novel, alternate proposal in which solar thermal power is used to power an electric-driven compression chiller and a heat-driven absorption chiller; as a pair of units, which would replace 2 Centrifugal chillers. The concept is found to be economically viable as a CDM project. The simple payback period works out to be 2 1/2 years. The investments required are large which can be brought down if the cost of solar concentrator is reduced.

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Audivet Durán, Cinthia, i Marco E. Sanjuán. "On-Line Early Fault Detection of a Centrifugal Chiller Based on Data Driven Approach". W ASME 2016 10th International Conference on Energy Sustainability collocated with the ASME 2016 Power Conference and the ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/es2016-59291.

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A district cooling system (DCS) is a system that distributes thermal energy through chilled water from a central source to residential, commercial, or industrial consumers, designated to air conditioning purposes. It is one of the most important part of a heating, ventilation, air conditioning and refrigeration systems (HVAC), because a DCS is composed of: Cooling towers, central chiller plant, water distribution systems and clusters of consumer buildings. This research is focused on the central chiller plant, due to it accounts for a substantial portion of the total energy consume of DCS and HVAC systems. The performance of central chiller plant is often affected by multiple faults which could be caused during installation or developed in routine operation. These non-optimal conditions and faults may cause 20–30% waste of energy consumption of HVAC&R systems. Automated fault detection and diagnosis (AFDD) tools have potential to detect an incipient fault and help to reduce undesirable conditions and energy consumption, and optimize the facility maintenance. We propose an online data driven fault detection strategy for district cooling system. The main objective is to develop an automated fault detection tool based on historical process data, which can be applied in transient operation. The proposed hybrid strategy is based on unsupervised and supervised learning techniques, and multivariate statistic techniques. Its aim is to identify the operating states of the chiller and evaluate the fault occurrence depending of its current operating state. This strategy uses the K-means clustering method, Naive Bayes classifier and Principal Component Analysis (PCA). The developed strategy was evaluated using the performance data of a 90-ton water-cooled centrifugal chiller (ASHRAE RP-1043) and also evaluated using a dynamic model of a chiller (Simscape™.) under similar conditions. The results show the advantages of novel early fault detection technique compared to Conventional PCA method in terms of sensitivity to faults occurrence and reduction of missed detection rate.

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Li, Pengfei, Yaoyu Li i John E. Seem. "Dynamic Modeling and Stability Analysis of Water-Cooled Centrifugal Chillers". W ASME 2010 Dynamic Systems and Control Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/dscc2010-4240.

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This paper presents a study on the dynamics of a water-cooled centrifugal chiller from two aspects: dynamic simulation modeling and stability analysis. First, the transient model is developed in Modelica with Dymola and the TLK/IfT Library (TIL). The centrifugal compressor is modeled in detail based on the turbomachinery theory. The chiller capacity control is achieved by the combination of variable inlet guide vane (VIGV) and variable speed drive (VSD). The shell-and-tube heat exchangers are discretized based on the finite volume method with convenient and numerically efficient two-phase property evaluations. A thermal expansion valve (TXV) is used to regulate the mass flow rate. These models are interconnected to form a centrifugal chiller system. Second, the stability of the chiller is studied based on Lyapunov analysis. The centrifugal chiller is effectively a “closed-loop” concatenation of the centrifugal compressor, condenser, expansion device and evaporator because the refrigerant flow stays within the closed path of the chiller system. The inherent unstable aspect of the compressor dynamics (e.g. surge) becomes more intrigued because the input and output flow are correlated, as compared to the typical “open-loop” centrifugal compressor applications such as compressed air systems or turbochargers. The Lyapunov stability analysis presented herein constructs partial foundation for future nonlinear control design for the centrifugal chiller systems.

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Gui, Fulin, Dwight D. Back, Robert P. Scaringe, Lawrence R. Grzyll i Joseph M. Gottschlich. "ZERO-ODP REFRIGERANTS FOR LOW TONNAGE CENTRIFUGAL CHILLER SYSTEMS". W Aerospace Atlantic Conference & Exposition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1996. http://dx.doi.org/10.4271/961320.

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Raporty organizacyjne na temat "Centrifugal chiller"

Evaluation of GSA maintenance practices of large centrifugal chillers and review of GSA refrigerant management practices. Gaithersburg, MD: National Institute of Standards and Technology, 1994. http://dx.doi.org/10.6028/nist.ir.5336.

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