Journal articles on the topic 'Chiller analysis'
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1
Sun, Xiao Yu, and Rui Li. "Numerical Simulation and Analysis of Energy Saving Operation of Chillers in an Air Conditioning System." Applied Mechanics and Materials 744-746 (March 2015): 2293–96. http://dx.doi.org/10.4028/www.scientific.net/amm.744-746.2293.
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The chiller’s operating energy consumption accounts for large proportion in energy consumption of air conditioning system. There are kinds of strategies can be used in the multiple chillers system. When running according to the load control of the chiller, different starting point and operating condition will affect the total energy consumption. Different operating conditions are put forward for a building chilled water system. According to simulate and analysis different operating condition, the optimum operation condition is concluded.
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Wang, Deming, Ying Peng, and Zexi Wang. "Adding a Bypass to Ensure the Chemical Plant Production." International Journal of Chemistry 8, no. 3 (July 5, 2016): 50. http://dx.doi.org/10.5539/ijc.v8n3p50.
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<p>The chilling output of the chiller fluctuated according to the chilling load. When it dropped down below a certain value, the temperature of the supply chilled water flowing out of the chiller would drop down too much. And this would result the chiller being shut down abnormally, because of its low temperature protection. Any this shutdown of the chiller endangered the production continuity and security, and caused a certain economic losses. A bypass, which was from the outlet of the chiller’s condenser to the chilled water filter inlet, was added to the chilling system. Through this bypass, some cooling water was introduced from the cooling water circulation into the chilled water circulation. Then the temperature of the supply chilled water flowing out of the chiller was promoted. With experiments, and by the aid of thermodynamics analysis, the amount of introduced cooling water, which could be introduced to promote the supply chilled water temperature for maintaining the chiller running normally, was researched. Ultimately, a certain amount of introduced cooling water, at which the chiller would no longer stop abnormally at any chilling load, was determined. And the energy lose caused by the introduced cooling water was less than 5 percent the rated output of the chiller. Compared with the chiller rated output, this energy lose was so small that it could be neglected.</p>
3
Ng, K. C., and X. L. Wang. "Thermodynamic methods for performance analysis of chillers." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 219, no. 2 (May 1, 2005): 109–16. http://dx.doi.org/10.1243/095440805x28249.
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This paper presents a simple thermodynamic model that captures accurately the behaviour of all types of real chillers or cooling devices. In addition to its predictive capability, it also provides a diagnostic means for the in situ monitoring of chiller performance. To enhance the understanding of the chiller cycles, a novel way of formulating the classic T-s diagrams is provided for all chiller types, ranging from the mechanical, heat-driven and solid-state chillers.
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George, Hezekiah, Jingdou Wang, and Becky Bryant. "Chiller compressor sound emission analysis." Journal of the Acoustical Society of America 151, no. 4 (April 2022): A84. http://dx.doi.org/10.1121/10.0010737.
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Building occupants rely on heating, ventilation, and air conditioning (HVAC) units for comfort. Chillers are HVAC units that serve the purpose of cooling a building. Because chillers are often placed on top of or near the building, the noise from the chiller can adversely affect the occupants. A crucial component of all chillers, the compressor, is responsible for the majority of the noise produced by the chiller. In addition to designing for cooling efficiency, engineers must also consider how quiet and acoustically efficient a chiller is. In this project, we aim to develop an enclosure to house the compressor, therefore, reducing the magnitude of noise that is emitted. We begin by studying an empty cavity model in an acoustical software and observing its modes, resonant frequencies, and corresponding pressure distributions. Next, we placed a sound source within the cavity and then analyzed the acoustics frequency response of the cavity without and with a sound-absorbent material. We then proceeded to analyze a FEM model of the compressor and its dynamic frequency response due to the bearing force. After further analysis of the compressor sound emission, simulations will be made for the compressor with the designed enclosure and sound-absorbent material.
5
Bai, Yan Bin, Xiang Huang, Hai Hong Huo, and Li Wen. "Evaporative Cooling Chillers Economic Configuration Scheme Analysis." Advanced Materials Research 516-517 (May 2012): 1152–55. http://dx.doi.org/10.4028/www.scientific.net/amr.516-517.1152.
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Depending on the project which will use the cooling system Combined with evaporative cooling chillers and mechanical chiller in yulin, the evaporative cooling chillers and mechanical chiller of water system were respectively analyzed in three different forms in this article. Starting from the different process of three different forms in Psychrometrics and the different running time, three different form of water system had been preliminary budgeted. It can be known that the economy of configuration scheme of evaporative cooling technology and mechanical refrigeration technology.
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Phu, Nguyen Minh. "Overall Optimization and Exergy Analysis of an Air Conditioning System Using a Series-Series Counterflow Arrangement of Water Chillers." International Journal of Air-Conditioning and Refrigeration 27, no. 04 (November 25, 2019): 1950034. http://dx.doi.org/10.1142/s2010132519500342.
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When water chillers are arranged in series-series counterflow (SSCF), the compressor lift of each chiller is decreased in comparison with that of water chillers in parallel. This means that the compressor power of SSCF chillers is lower than that of parallel chillers. In this paper, models of the main components in an air conditioning system were developed and verified to predict the behaviors of the whole system with respect to SSCF chillers. The results showed that performance was maximized with three SSCF chillers when the system was operated with normal set points. The performance was further improved to 26% and decreased with the number of SSCF chillers when the system was operated with optimal set points. The SSCF chiller system also demonstrated higher exergy efficiency regardless of the number of SSCF chillers. The irreversibility of components in SSCF chillers was rather low. However, the irreversibility of the cooling tower and cooling coil was slightly higher and lower, respectively, than those in the parallel chiller system.
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Hu, Jianke, Kai Teng, Yida Qiu, Yuzhu Chen, Jun Wang, and Peter Lund. "Thermodynamic and Economic Performance Assessment of Double-Effect Absorption Chiller Systems with Series and Parallel Connections." Energies 15, no. 23 (December 1, 2022): 9105. http://dx.doi.org/10.3390/en15239105.
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Absorption cooling technologies converting excess heat and renewable heat resources to cooling energy have shown progress in recent years. In this study, two 400 kW LiBr solution absorption chiller types with series and parallel connected are analyzed over a range of parameter values to better understand their applicability for different uses. Thermodynamic models for the components were constructed and validated. The performance of the chillers related to heat transfer, energy, exergy, and economy performance was comprehensively analyzed. The operating performance was investigated by considering the external variables, including inlet cooling water, chilled water, and inlet steam temperatures and the solution allocation ratio. The results indicate that the parallel connected chiller reaches higher energy and exergy performance than the series-connected chiller, but the heat transfer and economic performance was lower. The coefficient of performance and the exergy efficiency of the parallel chiller were for the reference system 1.30 and 24.42%, respectively. Except for the exergy efficiency, the inlet steam and inlet chilled water temperature had positive impact on the heat transfer, energy, and economic performance, while the inlet cooling water temperature trends the opposite. The sensitivity analysis on solution allocation ratio showed that a higher ratio decreases the heat transfer and economic performance, but considering the energy and exergy performance, a suitable allocation ratio would be 0.54.
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Maya Firanti Putri, Aris Sunawar, and Massus Subekti. "ANALISIS KINERJA CHILLER DI GEDUNG SENAYAN CITY." Journal of Electrical Vocational Education and Technology 1, no. 1 (March 20, 2020): 44–47. http://dx.doi.org/10.21009/jevet.0011.09.
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Abstract.
Research conducted in the building Senayan City in June 2016 using qualitative research methods. Standards are used as a benchmark the performance of each chiller uses ISO 6390 in 2011 on Energy Conservation Air system administration Building. These aspects are analyzed to determine the performance of the chiller is the temperature of chilled water, flow chilled water and compressor power. As for the influence of the three aspects is the temperature of the outside environment. By calculating the cooling capacity, the highest Coefficient of Permonace (COP) value can be determined each chiller.Chiller performance analysis results obtained COP value of the highest attainable number 1 at 7.31 chiller, chiller number 2 at 8.03 and chiller number 3 6:27. These values meet the mi nimum value of COP according to ISO standards. Lowest chiller COP value number 1 by 5.08, number 2 for 5.12 chiller and chiller number 3 at 4.22. Third party chiller COP minimum value does not meet the minimum standards of the COP. Chiller number 3 has the lowest minimum number COP and far below the minimum stadar.Judging from the value of cooling capacity and COP, chiller performance is not good enough is the number 3. And the chiller that has good enough performance is number 1 and 2
Abstrak
Penelitian ini bertujuan untuk menghasilkan data analisis kinerja chiller di gedung Senayan City. Penelitian yang dilakukan di gedung Senayan City pada bulan Juni 2016 ini menggunakan metode penelitian kualitatif. Standar yang digunakan sebagai patokan kinerja masing-masing chiller menggunakan SNI 6390 tahun 2011 tentang Konservasi Energi Sistem Tata Udara Bangunan Gedung. Aspek-aspek yang dianalisis untuk mengetahui kinerja chiller adalah temperatur chilled water, flow chilled water dan power kompresor. Adapun yang mempengaruhi ketiga aspek tersebut adalah temperatur lingkungan luar. Dengan menghitung kapasitas pendinginan, dapat ditentukan nilai Coefficient of Permonace (COP) tertinggi masing-masing chiller. Hasil analisis kinerja chiller didapat Nilai COP tertinggi yang dapat dicapai chiller nomor 1 sebesar 7,31, chiller nomor 2 sebesar 8,03 dan chiller nomor 3 6.27. Ketiga nilai tersebut memenuhi nilai minimum standar COP menurut SNI. Nilai COP terendah chiller nomor 1 sebesar 5,08, chiller nomor 2 sebesar 5,12 dan chiller nomor 3 sebesar 4,22. Ketiga nilai minimum COP ketiga chiller ini tidak memenuhi standar minimum COP. Chiller nomor 3 mempunyai angka minimum COP paling rendah dan jauh dibawah stadar minimum. Dilihat dari kapasitas pendinginan dan nilai COP, chiller yang kinerja kurang baik adalah chiller nomor 3. Dan chiller yang performanya cukup baik adalah chiller nomor 1 dan 2.
9
Dai, Ming He, Zhi Ping Zhou, and Xing Xue. "Test and Energy Consumption Analysis of Air-Conditioning Systems in Terminal Building of Guilin Liangjiang International Airport." Applied Mechanics and Materials 170-173 (May 2012): 2652–56. http://dx.doi.org/10.4028/www.scientific.net/amm.170-173.2652.
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In this paper, the operating conditions of air-conditioning systems in Terminal building of Guilin LiangJiang International Airport were tested and analysed. This paper mainly analyzes the influence of chilled water temperature on water chiller performance and derives the relationship of COP of water chiller and chilled water temperature difference between inlet and outlet , and provides reference for operation mode’s optimization of the air-conditioning system and energy consumption reduction of the whole building.
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Torres, Yamile Díaz, Paride Gullo, Hernán Hernández Herrera, Migdalia Torres del Toro, Mario A. Álvarez Guerra, Jorge Iván Silva Ortega, and Arne Speerforck. "Statistical Analysis of Design Variables in a Chiller Plant and Their Influence on Energy Consumption and Life Cycle Cost." Sustainability 14, no. 16 (August 16, 2022): 10175. http://dx.doi.org/10.3390/su141610175.
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An appropriate design of a chiller plant is crucial to guarantee highly performing solutions. However, several design variables, such as type of systems, total cooling capacity, and hydraulic arrangement, need to be considered. On the one hand, at present, different technical criteria for selecting the most suitable design variables are available. Studies that corroborate the influence of the design variables over the operational variables are missing. In order to fill this knowledge gap, this work proposes a statistical analysis of design variables in chiller plants operating in medium- and large-scale applications and evaluates their influence on energy consumption and life cycle cost (LCC) under the same thermal demand conditions. A case study involving 138 chiller plant combinations featuring different arrangements and a Cuban hotel was selected. The results suggested that the total chiller design and cooling capacity distribution among chillers have a significant influence on the energy consumption of the chiller plant with a Spearman’s Rho and Kendall Tau (τ) correlation index value of −0.625 and 0.559, respectively. However, with LCC, only the cooling capacity distribution among the chillers had a certain influence with a Kendall Tau correlation index value of 0.289. As for the considered total cooling capacity, the applied statistical test showed that this design variable does not have any influence on performing the chiller plant.
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Tan, Chao Yi, Peng Fei Yang, Meng Meng Wang, Hai Hua Hu, and Guo Qiang Zhang. "Efficiency Analysis of Series Connection Ground Source Heat Pump Water Chiller-Heater Unit." Applied Mechanics and Materials 529 (June 2014): 625–29. http://dx.doi.org/10.4028/www.scientific.net/amm.529.625.
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In order to improve EER of the ground source heat pump system and reduce heat transfer area of the ground heat exchanger, the authors had developed a series connection ground source heat pump water chiller-heater unit, after theoretical analyses, proved that placing the water chilled in front of the hot water unit could acquire a higher EER comparing to the opposite. In the meantime, this unit had a higher EER than a common water chiller-heater unit or a water chiller-heater unit with condensing heat recovery device. In an air conditioning system of ground source heat pump, employing the above mentioned unit can also reduce heat transfer area of the ground heat exchanger. It suggested that series connection ground source heat pump water chiller-heater unit is a kind of technology with a great development potential.
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Villa, Alvaro Antonio Ochoa, José Carlos Charamba Dutra, Jorge Recarte Henríquez Henríquez, Carlos Antonio Cabral do Santos, and José Ângelo Peixoto da Costa. "Dynamic experimental analysis of a LiBr/H2O single effect absorption chiller with nominal capacity of 35 kW of cooling." Acta Scientiarum. Technology 41, no. 1 (January 4, 2019): 35173. http://dx.doi.org/10.4025/actascitechnol.v41i1.35173.
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This work aims to transient performance of chiller single effect absorption refrigeration using the LiBr/H2O pair with nominal capacity of 35 kW. The goal of this study is to verify the absorption chiller when subjected to thermal loads and it transiently responsive as a function of the temperatures of the chilled, hot and cold water of the system. An experimental methodology was established in a micro-CHP laboratory to simulate the dynamic operating conditions of the system considering the thermal load (chilled water), the activation source (hot water) and the heat dissipation circuit (cold water). The thermal load was simulated from a set of electrical resistors installed in a water heater and the activation of the chiller from recovery gas a microturbine 30 kW and through a compact heat exchanger, where water is heated and stored in a hot buffer tank. The absorption chiller heat dissipation system consists of the pump and cooling tower. The system responded appropriately to the thermal load imposed providing COP values in the transient regime of 0.55 to 0.70 the temperature conditions tested.
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Zhang, Zhiping, Hongye Qiu, Dantong Li, Zhilong He, Ziwen Xing, and Lijian Wu. "Development of Ultra-High-Efficiency Medium-Capacity Chillers with Two-Stage Compression and Interstage Vapor Injection Technologies." Energies 15, no. 24 (December 16, 2022): 9562. http://dx.doi.org/10.3390/en15249562.
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Chillers are widely used in commercial buildings for air conditioning, and their energy consumption is the main contribution to the building’s carbon emissions. Currently, the COPs of small- and medium-capacity screw chillers are still generally lower than 6.5, whereas large-capacity commercial centrifugal chillers have achieved an ultra-high energy-efficiency level of COP ≥ 7.0. To achieve an ultra-high energy efficiency of COP ≥ 6.5 in medium-capacity chillers, the authors developed a 200 RT screw chiller by adopting the technologies of two-stage compression and interstage vapor injection. The whole development process, including the design, simulation, analysis, and experiment, is presented in this paper. It was found that the two-stage compression technology could effectively boost the performance of the chiller’s compressor to a maximum volumetric and adiabatic efficiency of 99% and 80%, respectively. With the interstage vapor injection technology, the chiller’s cooling capacity and COP were increased by more than 11% and 8%, respectively. When the use of these two technologies was combined, the maximum COP of the chiller reached 7.17. Additionally, under these working conditions, the COP and integrated part-load value (IPLV) were 6.74 and 10.04, respectively. In all, the combination use of vapor injection and two-stage compression technologies shows great potential to improve the performance of chillers. The work and conclusions described here might provide an effective reference for the future development of high-efficiency small- and medium-capacity screw chillers.
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Ho, Wai Tung, and Fu Wing Yu. "Chiller system performance management with market basket analysis." Facilities 39, no. 9/10 (March 19, 2021): 667–87. http://dx.doi.org/10.1108/f-09-2020-0107.
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Purpose This study aims to apply association rule mining (ARM) to uncover specific associations between operating components of a chiller system and improve its coefficient of performance (COP), hence reducing the electricity use of buildings with central air conditioning. Design/methodology/approach First, 13 operating variables were identified, comprising measures of temperatures and flow rates of system components and their switching statuses. The variables were grouped into four bins before carrying out ARM. Strong rules were produced to associate the variables and switching statuses with different COP classes. Findings The strong rules explain existing constraints on practising chiller sequencing and prioritise variables for optimisation. Based on strong rules for the highest COP class, the optimal operating strategy involves rescheduling chillers and their associated components in pairs during a high load operation. Resetting the chilled water supply temperature is the next best strategy, followed by resetting the condenser water entering temperature, subject to operating constraints. Research limitations/implications This study considers the even frequency method with four bins only. Replication work can be done with other discretisation methods and different numbers of classes to compare potential differences in the bin ranges of the optimised variables. Practical implications The strong rules identified by ARM highlight associations between variables and high or low COPs. This supports the selection of critical variables and the operating status of system components to maximise the COP. Tailor-made optimisation strategies and the associated electricity savings can be further evaluated. Originality/value Previous studies applied ARM for chiller fault detection but without considering system performance under the interaction of different components. The novelty of this study is its demonstration of ARM’s intelligence at discovering associations in past operating data. This enables the identification of tailor-made energy management opportunities, which are essential for all engineering systems. ARM is free from the prediction errors of typical regression and black-box models.
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Zamhuri, Muhammad Ikhwan, Haslenda Hashim, and 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, no. 2 (December 10, 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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Panahizadeh, Farshad, Mahdi Hamzehei, Mahmood Farzaneh-Gord, and Villa Ochoa. "Thermo-economic analysis and optimization of the steam absorption chiller network plant." Thermal Science, no. 00 (2021): 58. http://dx.doi.org/10.2298/tsci200619058p.
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Absorption chillers are one of the most used equipment in industrial, commercial, and domestic applications. For the places where high cooling is required, they are utilized in a network to perform the cooling demand. The main objective of the current study was to find the optimum operating conditions of a network of steam absorption chillers according to energy and economic viewpoints. Firstly, energy and economic analysis and modeling of the absorption chiller network were carried out to have a deep understanding of the network and investigate the effects of operating conditions. Finally, the particle swarm optimization search algorithm was employed to find an optimum levelized total costs of the plant. The absorption chiller network plant of the Marun Petrochemical Complex in Iran was selected as a case study. To verify the simulation results, the outputs of energy modeling were compared with the measured values. The comparison with experimental results indicated that the developed model could predict the working condition of the absorption chiller network with high accuracy. The economic analysis results revealed that the levelized total costs of the plant is 1730 $/kW and the payback period is three years. The optimization findings indicated that working at optimal conditions reduces the levelized total costs of the plant by 8.5%, compared to the design condition.
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Yan, Chengchu, Qi Cheng, and Hao Cai. "Life-Cycle Optimization of a Chiller Plant with Quantified Analysis of Uncertainty and Reliability in Commercial Buildings." Applied Sciences 9, no. 8 (April 14, 2019): 1548. http://dx.doi.org/10.3390/app9081548.
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Conventional and most optimal design methods for chiller plants often address the annual cooling load distribution of buildings and their peak cooling loads based on typical meteorological year (TMY) data, while the peak cooling load only appears a few times during the life-cycle and the sized chiller plant usually operates within its low efficient region. In this paper, a robust optimal design method based on life-cycle total cost was employed to optimize the design of a chiller plant with quantified analysis of uncertainty and reliability. By using the proposed design method, the optimized chiller plant can operate at its highly efficient region under various cooling load conditions, and provide sufficient cooling capacity even alongside some equipment/systems with failures. The minimum life-cycle total cost, which consists of the capital cost, operation, and availability-risk cost, can be achieved through optimizing the total cooling capacity and the numbers/sizes of chillers. A case study was conducted to illustrate the detailed implementation process of the proposed method. The performance of this design method was evaluated by comparing with that of other design methods.
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Alonso, Serafín, Antonio Morán, Miguel Prada, Perfecto Reguera, Juan Fuertes, and Manuel Domínguez. "A Data-Driven Approach for Enhancing the Efficiency in Chiller Plants: A Hospital Case Study." Energies 12, no. 5 (March 2, 2019): 827. http://dx.doi.org/10.3390/en12050827.
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Large buildings cause more than 20% of the global energy consumption in advanced countries. In buildings such as hospitals, cooling loads represent an important percentage of the overall energy demand (up to 44%) due to the intensive use of heating, ventilation and air conditioning (HVAC) systems among other key factors, so their study should be considered. In this paper, we propose a data-driven analysis for improving the efficiency in multiple-chiller plants. Coefficient of performance (COP) is used as energy efficiency indicator. Data analysis, based on aggregation operations, filtering and data projection, allows us to obtain knowledge from chillers and the whole plant, in order to define and tune management rules. The plant manager software (PMS) that implements those rules establishes when a chiller should be staged up/down and which chiller should be started/stopped according different efficiency criteria. This approach has been applied on the chiller plant at the Hospital of León.
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Simbolon, Luga Martin, and Yudi Prana Hikmat. "Comparison of Utilization an Absorption and Vapour Compression Chiller in Sub-Tropical Country Building – A Feasibility Study." Current Journal: International Journal Applied Technology Research 1, no. 1 (April 17, 2020): 23–37. http://dx.doi.org/10.35313/ijatr.v1i1.21.
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The present study investigate the feasibility of absorption chiller utilization as part of trigeneration system that possibly applied in sub-tropical country building. Trigeneration is refer to the heat utilisation from electric generator (combined heat and power, CHP) to generate absorption chiller in order to produce chilled water for air conditioning system (combined cooling, heat and power, CCHP). Compare to the vapour compression system, absorption chiller that is mainly generated by heat waste, promised benefit economically and environmentally. Overall efficiency of CCHP can reach 71 % and possibly reducing emission until 146709.07 kg CO2. Economic analysis using the Payback period methodology has shown that the CCHP would produce a return on investment of 2.6 years. Improvements absorption chiller and support from government are expected to lead to increased return on investment and improved viability of the system.
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G. L., David, Sodiki J. I., and Nkoi B. "Performance Evaluation of a Chiller Plant in a Bottling Company." International Journal for Research in Applied Science and Engineering Technology 11, no. 1 (January 31, 2023): 601–10. http://dx.doi.org/10.22214/ijraset.2023.48610.
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Abstract: This study is focused on the performance evaluation of a water-cooled chiller. Exergy analysis of a water-cooled chiller was carried out in order to identify the contributions of individual components to the total exergy destruction. The second law efficiency of each component as well as the exergetic efficiency of the chiller were assessed. Data were taken at two-hour intervals (six readings daily) for thirty days. Data obtained from the chiller inventory records include suction and discharge pressure and temperature of the refrigerant in the compressor, as well as temperature and mass flow rates of cooling water and chilled water. Other properties of the refrigerant were obtained from ammonia property table. From the results obtained, the compressor was identified as the largest contributor to exergy destruction (about 59% of the total exergy destruction in the chiller), the evaporator contributed about 16%, the condenser contributed 20% while the throttle valve contributed the least to exergy destruction (5%). It was ascertained that the evaporator has the highest second law efficiency of 70.29%, while the efficiencies of the compressor and condenser were 60.01% and 36.09%, respectively. The average exergetic efficiency of the chiller was found to be 35.10%. The overall results reveal that the potential capacity of the chiller remained unutilized. Measures to improve the performance indices and overall efficiency of the chiller have been suggested in this study
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Chen, Ching Liang, and Yung Chung Chang. "Power Consumption Saving of Chiller Water System for Semiconductor Factory in Taiwan." Advanced Materials Research 314-316 (August 2011): 1492–501. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.1492.
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Recently, the semiconductor manufacturing industry has exhibited not only fast growth, but intense power consumption. Consequently, reducing power consumption is critical for running reliability. A view of literature reveals that the power consumption of facility system is 56.6 % in the fabs. Among all facility systems, chiller plants are the largest energy users, consuming 27.2 % of the total power consumption. Therefore, saving power consumption for chiller plants involves a considerable economic benefit. In addition, cooling the water temperature further improves the efficiency of chillers. Hence, this report analyzes the optimal temperature between the chiller and cooling tower. Currently, controlling the chiller and cooling tower are separate processes, though, in fact, they should not be. This is because the water cooling temperature affects the efficiency of the chiller. Each reduced degree of the chiller condenser temperature reduces the electrical power by approximately 2 % in the cooling tower, in contrast to the chiller. Therefore, the optimal water cooling water temperature must be analyzed. The analysis method in this report is linear regression. First, determine the equations of power consumption for the chiller and cooling tower with variables representing the water cooling temperature, water supply temperature of the chiller, and outdoor loading and wet-bulb temperatures. Second, add the coefficient of the same variable to obtain the total power consumption equation for the chiller and cooling tower. The result shows the relationships of power consumption with water cooling temperature under identical conditions of the water cooling temperature, water supply temperature of chiller, and outdoor loading and wet-bulb temperatures. Finally, use the differential method to determine the optimal water cooling temperature.
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Kaya, A., and A. Sommer. "Energy Management of Chillers by Multilevel Control and Optimization." Journal of Dynamic Systems, Measurement, and Control 107, no. 4 (December 1, 1985): 270–77. http://dx.doi.org/10.1115/1.3140735.
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This paper deals with multilevel control and optimization of a chiller system. The system consists of multiple chillers, feed pumps, and cooling towers. A multilevel control structure is presented. The first level contains control loops for chilled water temperature, vane position, and condenser water temperature. Second level controls provide supervisory adjustments of set points of first level controls. Third level is optimum load allocation of chillers and pumps. A fourth level supervisory deals with the coordination of conflicting goals of subsystems to provide a load strategy. Performance analysis (monitoring, trouble shooting) are also presented. A digital and distributed control system is utilized for implementation. The distributed system has a flexible architecture compatible for each level of control sophistication. It offers simple function blocks for digital control of first-level loops, as well as, the higher levels without any need of computer programming.
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Wang, Zhi Wei, Zhan Wei Wang, and Zeng Feng Yan. "A Fault Diagnosis Model and its Application in Chiller Operating." Applied Mechanics and Materials 291-294 (February 2013): 1851–56. http://dx.doi.org/10.4028/www.scientific.net/amm.291-294.1851.
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The chiller performance decrease with the system operating is inevitable, however, determining how to predict when it will happen, and how to identity the degree of performance decline, it is very important to solve these actual problems for chiller high efficiency operating and daily management. This paper developed a fault diagnosis model based on thermodynamic analysis of chiller’s refrigeration cycle and heat transfer analysis of its heat exchangers, taking three projects which involve different source sinks, namely, air source, ground source and reclaimed water source as cases study, described the fault diagnosis method and implementation steps through these engineering cases, the results show that the fault diagnosis model provides a newly simple and effective approach for chiller operation monitoring.
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Bujok, Tomasz, Marcin Sowa, Piotr Boruta, Łukasz Mika, Karol Sztekler, and Patryk Robert Chaja. "Possibilities of Integrating Adsorption Chiller with Solar Collectors for Polish Climate Zone." Energies 15, no. 17 (August 26, 2022): 6233. http://dx.doi.org/10.3390/en15176233.
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Solar-powered adsorption chillers are a particularly interesting alternative to energy-intensive conventional refrigeration systems. Integration of the adsorption chiller with solar collectors is a very promising concept since the increase in solar radiation coincides with the increased demand for cooling. Such a solution is very economical and environmentally friendly. It also fits in with current trends related to energy policy and sustainable development. The article presents the results of tests conducted for a two-bed adsorption chiller integrated with solar collectors. The tests were performed on selected days of the summer period (July and August) at the KEZO Research Centre PAS in Jablonna (Poland). Based on the results obtained, the performance parameters of the adsorption chiller were determined, and the problems associated with the integration of all components of the system were identified and discussed. The values of the determined Coefficient of Performance (COP) and cooling capacity for the tested adsorption chiller are, depending on the day on which the tests were conducted, from 0.531 to 0.692 and from 5.16 kW to 8.71 kW, respectively. Analysis of the test results made it possible to formulate conclusions related to the design of integrated systems of adsorption chillers with solar collectors.
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Yu, F. W., and K. T. Chan. "Application of Direct Evaporative Coolers for Improving the Energy Efficiency of Air-Cooled Chillers." Journal of Solar Energy Engineering 127, no. 3 (July 20, 2005): 430–33. http://dx.doi.org/10.1115/1.1866144.
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This paper describes how direct evaporative coolers can be used to improve the energy efficiency of air-cooled chillers in various operating conditions and with different strategies for staging condenser fans. These coolers are installed in front of air-cooled condensers to precool outdoor air before entering the condensers. A simulation analysis on an air-cooled chiller equipped with a direct evaporative cooler showed that when head pressure control is used, the cooler enables the condensing temperature to drop by 2.1–6.2°C, resulting in a 1.4-14.4% decrease in chiller power and a 1.3–4.6% increase in the refrigeration effect. When the chiller with the cooler operates under condensing temperature control, where condenser effectiveness is enhanced by staging all condenser fans, there is a savings in chiller power of 1.3-4.3% in some operating conditions in which the drop in compressor power exceeds the additional condenser fan power due to the pressure drop across the cooler.
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Wu, Wu Chieh, Tzong Shing Lee, and Chich Hsiang Chang. "Improved Energy Performance of Air-Cooled Liquid Chillers with Innovative Condensing-Coil Configurations." Applied Mechanics and Materials 284-287 (January 2013): 785–89. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.785.
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The purpose of this study was to develop mathematical models for air-cooled chillers and their components using innovative varied row configurations as a parameter analysis model followed by a simulation of actual operational performance. In this manner, we were able to observe the increase in performance of air-cooled chillers and the energy transfer efficiency of individual components. This study found that the innovative varied row configuration (Type C) can increase the COP of air-cooled chiller by 6.7% over that of traditional condensing-coil configuration (Type A) with an increase in total irreversibility and the irreversibility of the condenser of 8.4% and 4.1%, respectively; Type C can increase the COP of air-cooled chiller by 3.3% over that of the best condensing-coil configuration (Type B) with an increase in total irreversibility and the irreversibility of the condenser of 1.6% and 4.6%, respectively. We believe that the results of this research can provide an important basis of reference for future design of air-cooled chiller units.
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Villa, Alvaro Antonio Ochoa, José Ângelo Peixoto da Costa, and Carlos Antonio Cabral dos Santos. "Energetic Analysis using theoretical modeling and the characteristic equation method in a small absorption chiller with LiBr/H2O." Acta Scientiarum. Technology 40, no. 1 (April 26, 2018): 34969. http://dx.doi.org/10.4025/actascitechnol.v40i1.34969.
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This paper sets out to examine a small absorption chiller that uses the pair LiBr/ H2O with a 4.5 kW nominal capacity, using theoretical modeling and the characteristic equation method. The idea is to compare two ways of simulating and evaluating absorption systems by analyzing the temperatures and flow rates of external hot, chilled and cold water circuits, as well as the values of the overall heat transfer coefficients of each component. Energetic analysis is based on conserving mass and energy by taking into consideration the overall heat transfer coefficients and their respective areas via the UA products of the 5 components of the absorption chiller. The characteristic equation method is based on Duhring’s rule of the internal temperature which is founded on saturation mean temperatures and the Duhring coefficient (B). The results of comparing the activation of thermal power and the cooling capacity of the Rotartica absorption chiller, obtained by theoretical modeling and from the characteristic equation values, were good since the mean relative errors found were 4% lower for most of the operating conditions examined.
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Sztekler, Karol, Wojciech Kalawa, Wojciech Nowak, Sebastian Stefański, Jarosław Krzywański, and Karolina Grabowska. "Using the adsorption chillers for waste heat utilisation from the CCS installation." EPJ Web of Conferences 180 (2018): 02106. http://dx.doi.org/10.1051/epjconf/201818002106.
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Worldwide tendencies in the scope of environmental protection demonstrate the requirement for the limited carbon dioxide emission, that influences on the development of greenhouse effect. As a result of coal as a basic fuel used in the professional power industry, this industry sector is the greatest CO2 polluter and it means that works on the reduction of carbon dioxide in such industry are completely justified. In the IPSEpro programming environment, a reference block model for a conventional coal power station was elaborated, including the CO2 separation unit basing on the adsorption methods with the CO2 preparation installation to liquid state. Simulation researches were conducted with means of numeric techniques, that enabled the system analysis for the CO2 separation unit with the CO2 preparation system to the liquid state, as well as analysis was made for the use of chiller systems, basing on the adsorption technology for waste heat use originating from the compression of CO2 in a cascade system, as well as for potential opportunities for further exploitation of the produced chilled water in the CCS cycle. We analysed in these papers the opportunities for chiller systems application, based on the adsorption chillers in the CCS installation used for the reduction of CO2 emission in the coal power station and its influence on the operation of a power station cycle.
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Kumbhar, Anil, Nitin Gulhane, and Sachin Pandure. "Theoretical Analysis of Hybrid Chiller." Energy Procedia 109 (March 2017): 487–96. http://dx.doi.org/10.1016/j.egypro.2017.03.082.
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V. Harika and Dr. K. Vasantha Kumar. "Modeling and Performance Analysis of AC Plant Heat Exchanger." September 2021 7, no. 09 (September 27, 2021): 35–40. http://dx.doi.org/10.46501/ijmtst0709007.
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AC plant Chiller is considered as a shell-and-tube heat exchanger and generally applied in a water-cooled chiller. These days shell and tube heat exchanger (STHX) is the most common type of heat exchanger broadly used in marine ships, due to its high pressure application. The AC plants fitted on-board Marine ships consist of a Chiller i.e. parallel flow heat exchanger with baffles. It is important to improve the performance of a chiller so that the usage of electrical energy can be reduced while the quality of a product can be increased. The water is cooled by using refrigerant in this chiller. This project mainly deals with modeling the prototype of basic geometry of shell and tube heat exchanger using Solidworks and meshing using simulation run using CFD package ANSYS. In this paper, by varying the number of baffles and different fluids they are water, R134a and R410a their performance of the chiller is studied. In this work, effect of the baffle spacing on the performance of a heat exchanger has been examined. Thermal and fatigue analysis is done in ANSYS for two materials Aluminum and Copper for better fluid at from CFD analysis.
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Nugraha, Anggara Trisna, and Lailia Nur Safitri. "Optimization of Central Air Conditioning Plant by Scheduling the Chiller Ignition for Chiller Electrical Energy Management." Indonesian Journal of electronics, electromedical engineering, and medical informatics 3, no. 2 (May 29, 2021): 76–83. http://dx.doi.org/10.35882/ijeeemi.v3i2.7.
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Currently, the demand for electrical energy in homes, buildings, and industry is increasing, in line with population and economic growth. Of course, because of the massive use of electrical energy, it is necessary to increase efficiency. Large shopping malls in some countries are the biggest consume electricity, especially when it comes to cooling systems. Therefore, it is necessary to save energy in shopping centers. Because there are still few tenants and shopping centers that are relatively quiet, the mall's energy consumption is low, so it requires increasing energy-efficient consumption efficiency by optimizing power management and calculating the chiller performance coefficient (COP). This research aims to increase the chiller performance coefficient (COP) to save energy in shopping centers. The optimization method used is to make changes to the chiller ignition schedule when it's used in malls. Through the analysis from this research, it was found that the COP increased to 0.584, and the value before optimization was 6.181. With increasing COP, the chiller performance will increase. The effect of increasing the chiller's performance could optimize the electrical energy efficiency of the chiller in 138.82 kWh/day
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Deymi-Dashtebayaz, Mahdi, and Parisa Kazemiani-Najafabad. "Energy, Exergy, Economic, and Environmental analysis for various inlet air cooling methods on Shahid Hashemi-Nezhad gas turbines refinery." Energy & Environment 30, no. 3 (August 15, 2018): 481–98. http://dx.doi.org/10.1177/0958305x18793112.
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In this paper, the effects of various compressor inlet air cooling methods to increase the performance of Shahid Hashemi-Nezhad gas turbines refinery were investigated. These methods included media, fogging, and absorption chillers as common inlet air cooling methods and pressure drop station as novel cooling method. By using the exergy, environmental, and economic analysis, the best method for compressor inlet air cooling was selected. Based on the results, the absorption chiller system had the highest compressor inlet air temperature drop and increased the thermal and exergy efficiencies of cycle by about 2.5 and 3%, respectively, in hot season. Using absorption chiller, pressure drop station, fogging, and media had further reduction in CO2 and CO than simple gas turbine, respectively. Finally based on the net present value and internal rate of return coefficients, the pressure drop station method is the most economically feasible option.
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Lau, Chammy, Irini Lai Fun Tang, and Wilco Chan. "Waterfront Hotels’ Chillers: Energy Benchmarking and ESG Reporting." Sustainability 13, no. 11 (June 1, 2021): 6242. http://dx.doi.org/10.3390/su13116242.
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Chillers consumes the largest amount power in subtropical hotels. To monitor chillers’ power usage is of critical importance in energy control. This study attempted to establish the benchmark of electricity usage of hotel chillers and elucidate how the benchmarking results can be integrated with the various types reports for monitoring purposes. A survey of 20 waterfront hotels in the city of Greater Bay Area was conducted and 13 complete samples were used in the analysis. Multiple regression with selected 12 parameters—outdoor temperature, solar radiation, wind speed, cooling degree days, room occupancy, number of employees, service types, and unequally sized chillers were employed. The investigation found that the mean electricity usage of a chiller is 118 kWh/m2 on an annual basis for a deluxe waterfront hotel. The analysis excluded air-conditioned floor area, an exploratory variable, as the valid factor in the chiller’s electricity usage. While the overall R2 of the modeling equation for the whole year was limited to 0.76, the explanatory power of equations for humid spring and deep summer reached 80%. Hoteliers may harness this exercise as a reference to monitor and report the performance of key energy production facility per the Environment, Social, and Governance (ESG) guide.
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Marjianto, Agus, Hafthirman Hafthirman, and Prihadi Setyo Darmanto. "ENERGY AND COST SAVING POTENTIAL OF HOTEL AIR CONDITIONING USING MAGNETIC BEARING CHILLER IN JAKARTA." International Journal of Innovation in Mechanical Engineering and Advanced Materials 3, no. 1 (June 4, 2021): 1. http://dx.doi.org/10.22441/ijimeam.v3i1.11356.
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The use of magnetic bearing chillers in hotel air conditioning systems is an opportunity for energy or cost savings. This study will compare the electrical energy consumption and cost analysis of the centralized air conditioning system using magnetic bearing chiller that uses variable flow to another air conditioning system such as the centralized air conditioning using constant flow chiller and the VRF split air conditioning system at Hotel A in Jakarta. The calculation of energy consumption for each air conditioning system is carried out for a year. Meanwhile, the cost analysis will be carried out using the life cycle cost method for 20 years. The air conditioning system which has the least energy consumption and has the lowest life cycle cost is the best air conditioning system for this hotel building. The maximum cooling load that occurs in Hotel A is 3,281 kW. From the results of energy calculations and cost analysis, a centralized air conditioning system with magnetic bearing chiller with variable flow is the best choice to Hotel A or similar building to Hotel A, with IKE (Intensitas Konsumsi Energi) value of 84 kWh/(m2.year), and a total cost of 78,873,678,478.00 IDR for a period of 20 years.
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Voloshchuk, Volodymyr, Olena Nekrashevych, Volodymyr Voloshchuk, and Pavlo Gikalo. "Exergy analysis of a reversible chiller." Modeling Control and Information Technologies, no. 5 (November 21, 2021): 105–6. http://dx.doi.org/10.31713/mcit.2021.33.
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The work presents the results of exergetic analysis of a reversible chiller providing both cooling and space heating in varying operational modes. The year values of avoidable parts of exergy destruction occurring in each system component are used for the analysis. The outcomes obtained showed that the both inside and outside heat exchangers have the highest priority for improvement revealing more than 718 kW-hr avoidable year exergy destruction within the system.
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Liao, Yundan, Yongjun Sun, and Gongsheng Huang. "Robustness analysis of chiller sequencing control." Energy Conversion and Management 103 (October 2015): 180–90. http://dx.doi.org/10.1016/j.enconman.2015.06.060.
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Liao, Yundan, Gongsheng huang, Yongjun sun, and Linfeng zhang. "Uncertainty analysis for chiller sequencing control." Energy and Buildings 85 (December 2014): 187–98. http://dx.doi.org/10.1016/j.enbuild.2014.09.037.
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Assadi, Morteza Khalaji, Hamidreza Akhavan Armaki, and Mahmoud Zendeh Del. "Technical-Economic Analysis of Steam Double Effect Absorption Chiller-Heaters Equipped with Solar Heat Pipe System." Applied Mechanics and Materials 465-466 (December 2013): 327–34. http://dx.doi.org/10.4028/www.scientific.net/amm.465-466.327.
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The aim of this research is to indicate a steam double effect chiller-heater equipped with solar heat pipe in a certain space with the area of 975 m2 located in Tehran, which is currently equipped with a direct-fired single effect absorption chiller-heater. Thereafter , the most obvious differences of the two chiller-heater systems are compared: the solar cooling system increases coefficient of performance as high as 0.54, decreases CO2 dissemination by 829 tons in each year, and reduces energy consumption by 1552.42 MWh/Yr. Economic analysis of the two systems using break-even-point showed that the use of solar system is attractive in applications that have excess thermal energy, and the conversion of this energy to higher value energy markets is to be more profitable than absorption gas-fired system from 13th year on. Keywords: Technical-economic analysis, energy optimization, solar chiller, absorption chiller-heater, solar heat pipe.
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Радченко, Андрей Николаевич, Анатолий Анатольевич Зубарев, Алексей Валерьевич Остапенко, and Артем Викторович Грич. "ПОВЫШЕНИЕ ЭФФЕКТИВНОСТИ УТИЛИЗАЦИИ ТЕПЛОТЫ ГАЗОВОГО ДВИГАТЕЛЯ СТУПЕНЧАТОЙ ТРАНСФОРМАЦИЕЙ." Aerospace technic and technology, no. 6 (December 20, 2018): 39–43. http://dx.doi.org/10.32620/aktt.2018.6.06.
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It was carried out the analysis of the heat utilization efficiency of the cogeneration module of the gas reciprocating engine with the cold produced by an absorption Li-Br chiller in an autonomous electric, heat and cold supply unit. It was revealed the presence of 30% heat losses of the total heat removed from the cogeneration gas reciprocating module and is due to the inconsistency of the joint operation modes of the absorption Li-Br chiller and the gas reciprocating engine. This inconsistency is caused by the contradictory conditions of their effective operation according to the temperature of the return coolant at the outlet of the absorption Li-Br chiller and at the entrance to the engine cooling system. The thermal state of the gas reciprocating engine is ensured by maintaining the temperature of the return (cooled) coolant not more than 70 °C at the inlet. At the same time, during the transformation of the coolant heat into the cold in an absorption Li-Br chiller, the temperature reducing in the machine is no more than 10 ... 15 °С, i.e. up to 75 ... 80 °С, if the temperature of the heat coolant at the outlet of the cogeneration gas reciprocating module (at the inlet of the absorption Li-Br chiller) is 90 °С. Due to the conflicting requirements for efficient operation of the gas reciprocating engine and absorption Li-Br chiller for the coolant temperature to maintain the temperature of the return coolant at the engine inlet at a safe level of 70 °C, it is additionally cooled in the "emergency heat release" cooling tower. It was studied the stage transformation of heat into cold applying ejector and absorption Li-Br chiller, and the evaporator section of the ejector chiller’s generator was on the coolant line before the absorption Li-Br chiller and the economizer section of the generator was on the coolant line after it. It was determined the dependence of the units’ cooling capacity increase on the thermal coefficient of the ejector chiller and the possibility of the unit’s cooling capacity increase by 10 ... 15% applying stage transformation of heat
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Alsarayreh, Ahmad A., Ayman Al-Maaitah, Menwer Attarakih, and Hans-Jörg Bart. "Energy and exergy analysis of combined cooling and power system using variable mode adsorption chiller." E3S Web of Conferences 294 (2021): 03002. http://dx.doi.org/10.1051/e3sconf/202129403002.
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Adsorption cooling is a promising technology to recover low-temperature waste heat from a diesel genset. In this paper, an advanced adsorption chiller working in variable mode is proposed for the combined cooling and power cycle (CCP) to recover waste heat from the water jacket in the diesel genset. The chiller works on three modes based on the ambient temperature for better heat utilization. In this study, three modes were investigated: single-stage cycle mode, short-duration, and medium-duration mass recovery modes. The results show that the energy and exergy efficiency for a single-stage cycle mode is higher at an ambient temperature lower than 35 °C . In comparison, the mass recovery mode has a higher energy and exergy efficiency at an ambient temperature higher than 35 °C. The annual energy and exergy efficiency for the CCP was investigated when the chiller works with variable modes based on the ambient temperature under DUBAI weather conditions as a case study. The results show an improvement of 14.7% and 14% of the energy and exergy efficiency, respectively, for CCP with a variable mode adsorption chiller compared to diesel genset alone. The results also show the CCP with variable mode adsorption chiller has a slight improvement on both energy and exergy efficiency compared to CCP with a single-stage adsorption chiller at the same ambient conditions.
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Al-Amir, Qusay R., and Nagham Y. Khudair. "THE ORETICAL ANALYSIS ON THE PERFORMANCE OF BRANCHED GAX CHILLER CYCLE." IRAQI JOURNAL FOR MECHANICAL AND MATERIALS ENGINEERING 18, no. 4 (January 6, 2019): 550–63. http://dx.doi.org/10.32852/iqjfmme.v18i4.230.
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In this study, a branched GAX absorption cycle operating with NH3-H2O pair has beeninvestigated to assess its performance under steady state conditions. The cycle modeling isimplemented using Engineering Equation Solver (EES) software. Analysis includesequations of mass, species and energy conservation. The analysis is used to simulate a GAXabsorption chiller utilization for air conditioning applications with a nominal capacity of 95TR. This chiller uses solar collectors as heat source. The operating parameters are selected atdifferent values of the heat source temperature (140 - 185°C), condenser exit temperature(30 to 48°C), evaporator exit temperature (2 to 11°C) ; split ratio (0 to 0.18); the difference inammonia concentration(0.25-036), mass flow rate in solution pump mr=1 kg/s; heatexchanger effectiveness ? ? 0.8. The results showed that the average COP is sensitive tooperating conditions where the average COP and cooling capacity of the branched GAXabsorption chiller increase with increasing generator and evaporator temperature whereasthey decrease with increasing condenser temperature. Simulation results also show that thesplit ratio and ammonia concentration difference have a significant impact on theperformance of absorption chiller.
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Ha, Ju-wan, Soolyeon Cho, Hwan-yong Kim, and Young-hak Song. "Annual Energy Consumption Cut-Off with Cooling System Design Parameter Changes in Large Office Buildings." Energies 13, no. 8 (April 19, 2020): 2034. http://dx.doi.org/10.3390/en13082034.
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A variety of greenhouse gas reduction scenarios have been proposed around the world to ensure sustainable developments and strengthen the global response to the climate change. To cope with this, it is urgently needed to reduce the amount of energy used for the heating, ventilating, air conditioning, and refrigerating (HVAC&R) systems in large buildings. This study discusses the reduction of cooling energy in large office buildings through the minimization of changes in components and equipment, such as heat source equipment and pumps, changes in the layout and operating methods of chilled water circulation pumps, and changes in the temperatures of chilled and condenser water. To do this, this study targeted an entire cooling system consisting of a hydronic system, a chiller, and a cooling tower, and conducted a quantitative analysis of the energy consumption and of the reduction achieved through a change in the pumping system type in the cooling system and a change in the Korean standard design and temperature of chiller and cooling tower via EnergyPlus simulations. The simulation results showed a cooling energy reduction of 103.2 MWh/yr, around 15.7%, where the primary constant-speed system (Case A) was changed to a primary variable-speed pump (Case B) in the configuration with a chilled water circulation pump. To reduce the cooling energy further, annually 142.3 MWh, around 21.7%, Case C in this study changed the outlet temperature of the chiller and temperature difference from 7 °C, 5 K to 9 °C, 9 K. Finally, when applying a change in the condenser water production temperature from 32 to 23.9 °C in accordance with ASHRAE Standard 90.1 for Case D, a cooling energy saving of 182.4 MWh/yr was observed, which is about 27.8%.
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Wells, Stephen M., Stephen A. Hambric, and Timothy A. Brungart. "Case study: Simulating and measuring the vibration and radiated sound of a large industrial chiller." Noise Control Engineering Journal 70, no. 3 (May 1, 2022): 207–30. http://dx.doi.org/10.3397/1/377017.
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This paper presents a case study for measuring and simulating the vibration and radiated sound for a large complex industrial chiller. We describe a simulation framework based on statistical energy analysis (SEA), which is populated using a hybrid mix of analytic, numerical, and measurement techniques. This hybrid approach was motivated by preliminary measurements of vibration and sound from the operating chiller, as well as a series of vibroacoustic transfer functions measured during quiescent non-operating conditions. Some components, like the chiller condenser shell, are modally dense and well suited to statistical estimates of SEA parameters like modal density and coupling between the shell modes and internal and external acoustic spaces. Other components, like the discharge pipe between the compressor and condenser shell, have only a few well separated modes with low damping. This component is better modeled using mobilities either measured or calculated using finite element analysis. We estimate other parameters like internal and coupling loss factors using a mix of analytics and measurements where appropriate. We validate the general model by comparing simulated and measured transfer functions between the discharge pipe and condenser shell — the components that radiated the most sound. We estimate structure-borne and fluid-borne input powers from the compressor using inference techniques based on transfer function measurements at quiescent conditions and averaged surface vibrations measured at operating conditions. This inference approach allows for estimating input powers over any chiller operating condition. Simulated vibrations and radiated sound are generally within 3 dB of measurements for several operating conditions. This case study provides a useful general methodology for modeling and measuring the vibroacoustics of chillers and other complex machinery
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PARK, CHAN WOO, DA YOUNG YOU, HYOUNG JIN KIM, and IK-TAE IM. "PERFORMANCE ANALYSIS FOR THE CHARACTERISTICS OF DOUBLE/SINGLE EFFECT HYBRID TYPE ABSORPTION CHILLER." International Journal of Air-Conditioning and Refrigeration 18, no. 01 (March 2010): 23–29. http://dx.doi.org/10.1142/s2010132510000046.
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In this study, the characteristics of the hybrid type absorption chiller, combined with the single effect absorption chiller and the double effect absorption chiller, are numerically studied to use waste hot water effectively. In the case of the full load for hybrid type absorption system, the concentration and temperature of LiBr solution increase about 2.2°C and 0.7%, respectively, at the single effect generator by the hot water. As the partial load decreases, the COP decreasing ratio of the hybrid type absorption chiller is higher than that of the double effect absorption chiller. On the other hand, COP f shows the opposite result of COP. The cycle COP of the hybrid type is about 1.07 on the full load which is 0.11 lower than that of the conventional double effect type. But COP f of the hybrid type is 1.28 which is 0.22 larger than that of double effect type. In the case of 50% partial load, COP f of the hybrid type is 2.66 and at below 50% partial load, system can be operated without any fuels. As the temperature of hot water and the mass flow ratio of hot water increase, the fuel saving ratio increases. The effect of the inlet temperature on the COP and COP f is much more significant than that of the mass flow rate of the hot water.
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Cansian, Rogério Luis, Salete Teresa Radeski Floriani, and Eunice Valduga. "Microbiological analysis of critical points in the chicken industry." Brazilian Archives of Biology and Technology 48, no. 3 (May 2005): 403–6. http://dx.doi.org/10.1590/s1516-89132005000300011.
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This work is focused on identifying microbial contamination in the scalding asepsis and cooling processes as well as in fresh sausages obtained. Salmonella was identified in two scald water samples but was absent in the water from chiller and in the final product, which might be explained in terms of chlorine addition and temperature reduction. The analysis revealed that MPN of Escherichia coli was in the range of <1-11/mL in the scald water and <1-64/mL in the chiller. Aeromonas sp. count showed 5 to 3.5x10¹ CFU/mL in the scald water and 9 to 3.7x10² CFU/mL in the chiller, probably due to the psycrophile characteristics of Aeromonas and evisceration process. The analysis of fresh sausages chicken revealed a sharp increase in the Aeromonas count (2.5x10³ CFU/g). Results showed the need of including Aeromonas analyzes in microbiological tests of foods.
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Kadam, Sambhaji T., Ibrahim Hassan, Mohammad Azizur Rahman, Athanasios I. Papadopoulos, and Panos Seferlis. "Review on Modeling of Vapor Compression Chillers: District Cooling Perspective." International Journal of Air-Conditioning and Refrigeration 28, no. 02 (June 2020): 2030003. http://dx.doi.org/10.1142/s2010132520300037.
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Energy consumption and its associated consequences can be reduced by implementing district cooling strategies that supply low temperature water to a wide range of end users through chillers and distribution networks. Adequate understanding, performance prediction and further optimization of vapor compression chillers used widely in district cooling plants have been a subject of intense research through model-based approaches. In this context, we perform an extensive review of different modeling techniques used for predicting steady-state or dynamic performance of vapor compression liquid chillers. The explored modeling techniques include physical and empirical models. Different physical models used for vapor compression chillers, based on physics laws, are discussed in detail. Furthermore, empirical models (based on artificial neural networks, regression analysis) are elaborated along with their advantages and drawbacks. The physical models can depict both steady- and unsteady-state performance of the vapor compression chiller; however, their accuracy and physical realism can be enhanced by considering the geometrical arrangement of the condenser and evaporator and validating them for various ecofriendly refrigerants and large system size (i.e., cooling capacity). Apparently, empirical models are easy to develop but do not provide the necessary physical realism of the process of vapor compression chiller. It is further observed that DC plants/networks have been modeled from the point of view of optimization or integration but no efforts have been made to model the chillers with multiple VCR cycles. The development of such models will facilitate to optimize the DC plant and provide improved control strategies for effective and efficient operation.
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Hao, Xuejun, and Tong Wang. "Simulation analysis of factors influencing chiller EER." Journal of Thermal Science 23, no. 3 (May 13, 2014): 285–89. http://dx.doi.org/10.1007/s11630-014-0708-4.
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Susilo, Aryudi, R. Ismet Rohimat, and Hennie Husniah. "Analisis Kegagalan Operasional Mesin Chiller dengan Metoda FTA dan FMEA." Integrasi : Jurnal Ilmiah Teknik Industri 4, no. 2 (October 23, 2020): 19. http://dx.doi.org/10.32502/js.v4i2.2871.
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Mesin air chiller adalah bagian dari sistem penyediaan dan penyediaan udara bersih dan dingin ke area bangunan. Kerusakan pada komponen mesin chiller telah mengurangi pasokan udara dingin ke area Mall. FTA (Fault Tree Analysis) dan FMEA (Failure Mode dan Effect Analysis) digunakan untuk melacak kasus-kasus kegagalan chiller engine, dengan penekanan pada analisis "pendekatan top-down", yang merupakan analisis menyeluruh mulai dari sistem tingkat atas dan meneruskannya turun, sehingga diharapkan dapat menjadi solusi yang tepat dalam menangani masalah pasokan udara dingin ke gedung Mall, dan dengan metode itu diharapkan juga dapat memberikan proposal dari penjadwalan pemeliharaan dengan membedakan perilaku penjadwalan sesuai dengan tingkat kritis dari masalah setiap unit komponen mesin chiller.
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Real-Fernández, Navarro-Esbrí, Mota-Babiloni, Barragán-Cervera, Domenech, Sánchez, Maiorino, and Aprea. "Modeling of a PCM TES Tank Used as an Alternative Heat Sink for a Water Chiller. Analysis of Performance and Energy Savings." Energies 12, no. 19 (September 24, 2019): 3652. http://dx.doi.org/10.3390/en12193652.
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Phase change materials (PCMs) can be used in refrigeration systems to redistribute the thermal load. The main advantages of the overall system are a more stable energy performance, energy savings, and the use of the off-peak electric tariff. This paper proposes, models, tests, and analyzes an experimental water vapor compression chiller connected to a PCM thermal energy storage (TES) tank that acts as an alternative heat sink. First, the transient model of the chiller-PCM system is proposed and validated through experimental data directly measured from a test bench where the PCM TES tank is connected to a vapor compression-based chiller. A maximum deviation of 1.2 °C has been obtained between the numerical and experimental values of the PCM tank water outlet temperature. Then, the validated chiller-PCM system model is used to quantify (using the coefficient of performance, COP) and to analyze its energy performance and its dependence on the ambient temperature. Moreover, electrical energy saving curves are calculated for different ambient temperature profiles, reaching values between 5% and 15% taking the experimental system without PCM as a baseline. Finally, the COP of the chiller-PCM system is calculated for different temperatures and use scenarios, and it is compared with the COP of a conventional aerothermal chiller to determine the switch ambient temperature values for which the former provides energy savings over the latter.
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Nisa, Elsa Chaerun, Yean-Der Kuan, and Chin-Chang Lai. "Chiller Optimization Using Data Mining Based on Prediction Model, Clustering and Association Rule Mining." Energies 14, no. 20 (October 11, 2021): 6494. http://dx.doi.org/10.3390/en14206494.
Full textAbstract:
The chiller is the major energy consuming HVAC component in a building. Currently, huge chiller data is easy to obtain due to Internet of Things (IoT) technology development. In order to optimize the chiller system, this study presents a data mining technique that utilizes the available chiller data. The data mining techniques used are prediction model, clustering analysis, and association rules mining (ARM) analysis. The dataset was collected every minute for a year from a water-cooled chiller at an institutional building in Taiwan and from meteorological data. The power consumption prediction model was built using deep neural networks with 0.955 of R2, 4.470 of MAE, and 6.716 of RMSE. Clustering analysis was performed using the k-means algorithm and ARM analysis was performed using Apriori algorithm. Each cluster identifies those operational parameters that have strong association rules with high performance. The operational parameters from ARM were simulated using the prediction model. The simulation result shows that the ARM operational parameters can successfully save the energy consumption by 22.36 MWh or 18.17% in a year.