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Cooling High Power Dissipating Artificial Intelligence (AI) Chips Using Refrigerant
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作者 Waheeb Mukatash Hussameddine Kabbani +4 位作者 Jochem Marc Massalt Matthew Moscoso Merari Mejia Robles Tyler Yang Charlie Nino 《Journal of Electronics Cooling and Thermal Control》 2024年第2期35-49,共15页
High power dissipating artificial intelligence (AI) chips require significant cooling to operate at maximum performance. Current trends regarding the integration of AI, as well as the power/cooling demands of high-per... High power dissipating artificial intelligence (AI) chips require significant cooling to operate at maximum performance. Current trends regarding the integration of AI, as well as the power/cooling demands of high-performing server systems pose an immense thermal challenge for cooling. The use of refrigerants as a direct-to-chip cooling method is investigated as a potential cooling solution for cooling AI chips. Using a vapor compression refrigeration system (VCRS), the coolant temperature will be sub-ambient thereby increasing the total cooling capacity. Coupled with the implementation of a direct-to-chip boiler, using refrigerants to cool AI server systems can materialize as a potential solution for current AI server cooling demands. In this study, a comparison of 8 different refrigerants: R-134a, R-153a, R-717, R-508B, R-22, R-12, R-410a, and R-1234yf is analyzed for optimal performance. A control theoretical VCRS model is created to assess variable refrigerants under the same operational conditions. From this model, the coefficient of performance (COP), required mass flow rate of refrigerant, work required by the compressor, and overall heat transfer coefficient is determined for all 8 refrigerants. Lastly, a comprehensive analysis is provided to determine the most optimal refrigerants for cooling applications. R-717, commonly known as Ammonia, was found to have the highest COP value thus proving to be the optimal refrigerant for cooling AI chips and high-performing server applications. 展开更多
关键词 Artificial Intelligence Thermal Control Server Systems Vapor Compression Refrigeration Cycle Server Cooling
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Effect of Refrigerant on the Performance of a C3/MRC Liquefaction Process
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作者 Xiao Wu Zhaoting Wang +2 位作者 Longfei Dong Yanping Xin Tianshu Yu 《Fluid Dynamics & Materials Processing》 EI 2023年第1期25-36,共12页
The Mixed Refrigerant(MR)component is an important factor influencing the performances of natural gas lique-faction processes.However,there is a lack of systematic research about the utilization of propane pre-cooled(... The Mixed Refrigerant(MR)component is an important factor influencing the performances of natural gas lique-faction processes.However,there is a lack of systematic research about the utilization of propane pre-cooled(C3/MRC).In this paper,this mixed refrigerant cycle liquefaction process is simulated using the HYSYS software and the main influential parameters involved in the process are varied to analyze their influence on the liquefaction rate and power consumption.The results show that an effective way for lowering the power consumption of the compressor consists of reducing the flow through the compressor through optimization of the percentage of mixed refrigerant.The power consumption of the compressor in the hybrid refrigeration process is affected by both flow and pressure ratios.Its specific power consumption can be reduced by increasing the flow and decreasing the pressure ratio at the same time.The increase in refrigerant pressure at the high-pressure end can significantly mitigate the energy loss of the heat exchanger and compressor. 展开更多
关键词 refrigerant C3/MRC process liquefaction performance power consumption pressure ratio hybrid refrigeration process
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Effect of surface microstructure of aluminum coating on corrosion properties of magnetic refrigerant gadolinium 被引量:1
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作者 吴红艳 刘剑 +3 位作者 赵浩峰 蒋琼 徐一 徐佳 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第11期3280-3285,共6页
AI coatings with different microstructures were prepared on the surface of Gd using the magnetron sputtering technique to improve its corrosion resistance. The corrosion behaviors for the pure Gd and Gd with Al coatin... AI coatings with different microstructures were prepared on the surface of Gd using the magnetron sputtering technique to improve its corrosion resistance. The corrosion behaviors for the pure Gd and Gd with Al coating in distilled water were studied using the mass loss and electrochemical performance. As a result, pure Gd without coating shows a certain amount of surface cracks under water flow conditions, whereas the polygonal Al coating decreases the path of the corrosive medium to body due to the existence of eroding pits structure. Compared with the polygonal structure Al coating and pure Gd, the lamellar structure of Al coating exhibits a higher electrochemical protection performance (e.g., a lower corrosion current and higher self-corrosion potential) and no occurrence of pitting corrosion. Due to an effective physical shield, the formation of the lamellar structure protected the inner Gd part from being corroded, and prolonged the duration of cathodic protection. 展开更多
关键词 corrosion resistance lamellar aluminum coating polygonal aluminum coating magnetic refrigeration pure gadolinium
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Comprehensive approach to predicting the circulation composition of zeotropic refrigerants 被引量:1
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作者 陈九法 《Journal of Southeast University(English Edition)》 EI CAS 2004年第3期315-318,共4页
The problem of composition shift in zeotropic fluid circulation, which is encountered in modern air conditioning and refrigeration systems, is studied. It reveals that the composition shift phenomena is contributed by... The problem of composition shift in zeotropic fluid circulation, which is encountered in modern air conditioning and refrigeration systems, is studied. It reveals that the composition shift phenomena is contributed by fractionation related to four mechanisms. This paper concentrates on the modeling of component fractionation in heat exchangers. Element approach is employed, and the amount of each component holdup is calculated element by element with a proper void fraction model. The circulation concentration is determined from the refrigerant differential holdup in heat exchangers. Simulations are carried out to prove the validity. The results can improve the reliability and efficiency in zeotropic refrigerant applications. 展开更多
关键词 Air conditioning COMPOSITION FRACTIONATION Heat exchangers REFRIGERATION
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Magnetic and magnetocaloric effect of Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass
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作者 于世霖 田路 +4 位作者 王俊峰 赵新国 李达 莫兆军 李昺 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期602-606,共5页
Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass exhibited excellent magnetic refrigeration material with a wide temperature range and high refrigeration capacity(RC)was reported.Er_(20)Ho_(20)Dy_(20)Cu_... Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass exhibited excellent magnetic refrigeration material with a wide temperature range and high refrigeration capacity(RC)was reported.Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass was observed with typical spin glass behavior around 15.5 K.In addition,we find that the magnetic entropy change(-△S_(M))originates from the sample undergoing a ferromagnetic(FM)to paramagnetic(PM)transition around 20 K.Under a field change from 0 T to 7 T,the value of maximum magnetic entropy change(-△S_(M)^(max))reaches 12.5 J/kg·K,and the corresponding value of RC reaches 487.7 J/kg in the temperature range from 6 K to 60 K.The large RC and wide temperature range make the Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass be a promising material for application in magnetic refrigerators. 展开更多
关键词 magnetic materials magnetocaloric effect high-entropy metallic glass magnetic refrigeration large refrigeration capacity
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A New Family of SO_(4)^(2–)-Templated 3d-4f High-Nuclearity Clusters:Syntheses,Structures,and Magnetic Properties
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作者 Caihong Fan Kaipeng Bai +4 位作者 Qiancheng Luo Tian Han Chang Huang Yanzhen Zheng Weipeng Chen 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2024年第20期2438-2444,共7页
The precise syntheses of transition-rare-earth metal clusters with desired structures remain a great challenge.Herein,by utilizing SO_(4)^(2-)anion released by in-situ decomposition of sodium dodecyl sulfate(SDS)as a ... The precise syntheses of transition-rare-earth metal clusters with desired structures remain a great challenge.Herein,by utilizing SO_(4)^(2-)anion released by in-situ decomposition of sodium dodecyl sulfate(SDS)as a template,a series of novel high-nuclearity 3d-4f clusters,formulated as[Ni_(24)Pr_(22)(μ_(3)-OH)_(31)(pida)_(24)(SO_(4))_(4)(NO_(3))_(9)(CH_(3)COO)_(3)]·Br_(4)·(NO_(3))_(11)·_(16)H_(2)O·25CH_(3)OH(1,H_(2)pida=N-phenyliminodiacetic acid),[Ni_(24)Nd_(22)(μ3-OH)_(31)(pida)_(24)(SO_(4))_(4)(NO_(3))_(9)(CH_(3)COO)_(3)]·Br_(4)·(NO_(3))_(11)·14H_(2)O·24CH_(3)OH(2)and[Ni_(24)Gd_(22)(μ3-OH)_(36)(bida)_(24)(SO_(4))_(7)(NO_(3))_(3)(CH_(3)COO)_(3)]·(SO_(4))·Br_(4)·(NO_(3))_(4)·31H_(2)O·32CH_(3)OH(3,H_(2)bida=N-benzyliminodiacetic acid),have been successfully isolated.X-ray crystal structure analyses reveal that all the cationic{Ni_(24)RE_(22)}cores in 1-3 possess a ball-like structure with C_(3v)symmetry,and can be viewed as consisting of an inner{RE_(22)}core and an outer{Ni_(24)}shell.From 1 and 2 to 3,due to the lanthanide contraction effect,the coordination numbers for rare-earth metal centers in{RE_(22)}are different,resulting in different number of SO_(4)^(2-)and NO_(3)^(-)anions to support and stabilize the skeleton structures.Meanwhile,the magnetic properties of complexes 1-3 were also studied.The result revealed that complexes 1-3 show antiferromagnetic/ferrimagnetic interactions,and 3 exhibits magneto-caloric effect at ultralow temperatures with a maximum-ΔSm(magnetic entropy change)value of 33.03 J·kg^(−1)·K^(−1)at 3.0 K and 7 T. 展开更多
关键词 Transition-Rare-earth metal Cluster Anionic template Magnetic exchange Magnetic refrigeration
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APPLICATION POSSIBILITY OF BINARY NONAZEOTROPIC REFRIGERANT IN JET REFRIGERATION *
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作者 张于峰 张利民 +1 位作者 李灿华 孙萍 《Transactions of Tianjin University》 EI CAS 1998年第1期26-30,共5页
This paper analyzes the possibility of applying binary nonazeotropic refrigerants in the jet refrigeration cycle. The thermodynamic cycle performance of two kinds of working pairs (R30/R142b, R30/R124) are calculated ... This paper analyzes the possibility of applying binary nonazeotropic refrigerants in the jet refrigeration cycle. The thermodynamic cycle performance of two kinds of working pairs (R30/R142b, R30/R124) are calculated using the EOS of PR equation of state, and the results are discussed. The theoretical calculations indicate that refrigerating quality can be improved if the binary mixtures evaporate just in the low temperature region. The character of the rejecter to compress two phase medium supports the possibility of this kind of cycle. 展开更多
关键词 jet refrigeration evaporating in low temperature region vapour liquid two phase compression binary nonazeotropic refrigerant
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Development of 400-μW cryogen-free dilution refrigerators for quantum experiments
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作者 关翔 樊洁 +2 位作者 边勇波 程智刚 姬忠庆 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期28-35,共8页
We have successfully developed cryogen-free dilution refrigerators with medium cooling power that can be applied to quantum experiments. Breakthroughs have been made in some key technologies and components of heat swi... We have successfully developed cryogen-free dilution refrigerators with medium cooling power that can be applied to quantum experiments. Breakthroughs have been made in some key technologies and components of heat switches and dilution units. Our prototype has been running continuously and stably for more than 100 hours below 10 m K, with a minimum temperature of 7.6 m K and a cooling power of 450 μW at 100 m K. At the same time, we have also made progress in the application of dilution refrigerators, such as quantum computing, low-temperature detector, and magnet integration. These indicators and test results indicate good prospects for application in physics, astronomy, and quantum information. 展开更多
关键词 cryogen-free dilution refrigerator quantum computing low-temperature detector superconducting magnet
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Optimization performance of quantum endoreversible Otto machines with dual-squeezed reservoirs
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作者 Haoguang Liu 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期198-204,共7页
We consider a quantum endoreversible Otto engine cycle and its inverse operation-Otto refrigeration cycle,employing two-level systems as the working substance and operating in dual-squeezed reservoirs.We demonstrate t... We consider a quantum endoreversible Otto engine cycle and its inverse operation-Otto refrigeration cycle,employing two-level systems as the working substance and operating in dual-squeezed reservoirs.We demonstrate that the efficiency of heat engines at maximum work output and the coefficient of performance for refrigerators at the maximum c criterion will degenerate toη-=η_(C)/(2-η_(C))andε-=(√9+8ε_(C)-3)/2 when symmetric squeezing is satisfied,respectively.We also investigated the influences of squeezing degree on the performance optimization of quantum Otto heat engines at the maximum work output and refrigerators at the maximum X criterion.These analytical results show that the efficiency of heat engines at maximum work output and the coefficient of performance for refrigerators at the maximum X criterion can be improved,reduced or even inhibited in asymmetric squeezing.Furthermore,we also find that the efficiency of quantum Otto heat engines at maximum work output is lower than that obtained from the Otto heat engines based on a single harmonic oscillator system.However,the coefficient of performance of the corresponding refrigerator is higher. 展开更多
关键词 quantum Otto heat engine quantum Otto refrigerator optimization performance dual-squeezed reservoirs
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Design and application of refrigerant recoveryand fillingcontrol system based on MSP430
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作者 李世光 李尧 +2 位作者 孟祥杰 张晓静 孙鸿 《Journal of Measurement Science and Instrumentation》 CAS 2014年第1期75-79,共5页
The control scheme of multifunctional refrigerant recovery and filling control system for air conditioning system is presented in this paper.The scheme of hardware circuit based on micro controller unit (MCU) MSP430... The control scheme of multifunctional refrigerant recovery and filling control system for air conditioning system is presented in this paper.The scheme of hardware circuit based on micro controller unit (MCU) MSP430 uses high-precision weighing sensor and high performance amplifier.The software program uses median average filtering algorithm.The device can recycle discarded refrigerant after purification and quantitative filling refrigerant.Meanwhile,the apparatus has the functions of recovery,filling,pressing,vaccumizing,refueling,etc.The system is proved to be of low cost,good stability and high practical value. 展开更多
关键词 refrigerant MSP430 weighing sensor FILTER
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Application of water loop variable refrigerant flow air-conditioning system in large-scale buildings in northern China
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作者 孙婷婷 倪龙 +1 位作者 姚杨 马最良 《Journal of Southeast University(English Edition)》 EI CAS 2010年第2期197-200,共4页
A water loop variable refrigerant flow(WLVRF)air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a va... A water loop variable refrigerant flow(WLVRF)air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a variable refrigerant flow(VRF)air-conditioning unit,a water loop and an air source heat pump.The water loop transports energy among different regions in the buildings instead of refrigerant pipes,decreasing the scale of the VRF air-conditioning unit and improving the performance.Previous models for refrigerants and building loads are cited in this investigation.Mathematical models of major equipment and other elements of the system are established using the lumped parameter method based on the DATAFIT software and the MATLAB software.The performance of the WLVRF system is simulated.The initial investments and the running costs are calculated based on the results of market research.Finally,a contrast is carried out between the WLVRF system and the traditional VRF system.The results show that the WLVRF system has a better working condition and lower running costs than the traditional VRF system. 展开更多
关键词 variable refrigerant flow air-conditioning system water loop large-scale building
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Intermodal Competition: Cargo Airships versus Long-Haul Trucking for Perishable Commodities
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作者 Barry Everett Prentice 《Journal of Transportation Technologies》 2024年第2期195-211,共17页
Intermodal competition changes with changes in technology, economics, and environmental concerns. Trucks and airships are generally considered not to be competitors, but this depends on the distance of haul. The tonne... Intermodal competition changes with changes in technology, economics, and environmental concerns. Trucks and airships are generally considered not to be competitors, but this depends on the distance of haul. The tonne-kilometer cost of trucking rises much more quickly with distance than it does the cost of a cargo airship. At some distance, the two modes are direct substitutes. The costs of the Mexico-Canada refrigerated truck supply chain are compared with the costs of a 100t-lift, electrically-powered airship. The flight characteristics of the Hindenburg Zeppelin are used as a model for a modern cargo airship. The supply chain cost of trucking tomatoes is used to test the theorical proposition. The cost difference works out to about US10¢/kg (5¢/lb) advantage for trucking Mexican tomatoes to Canada. However, this cost disadvantage of the airship could be made up by their vibrationless ride, better air circulation and one-day service versus four days by truck. This alternative form of transportation could have a positive impact on worldwide north-south distribution of food. Airships can overcome trade barriers and distance to open new markets for perishable food exports. In addition, they would reduce the carbon emissions of transport. Canada imports 160,000 refrigerated truckloads of fruits and vegetables by from the southern US and Mexico. With an average driving distance of 3,000 km, these trucks emit 606,000 MT of CO<sub>2</sub> annually. Airships powered by hydrogen fuel cells would have zero-carbon emissions. Markets are not yet incorporating the environmental advantage of airships in any freight comparison, but inevitably this will be important. 展开更多
关键词 AIRSHIP Refrigerated Trucks Mexico Tomatoes Carbon-emissions Perishables
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A Review on Technologies for the Use of CO2 as a Working Fluid in Refrigeration and Power Cycles
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作者 Orelien T. Boupda Hyacinthe D. Tessemo +3 位作者 Isidore B. Nkounda Fongang Francklin G. Nyami Frederic Lontsi Thomas Djiako 《Energy and Power Engineering》 2024年第6期217-256,共40页
The use of carbon dioxide as a working fluid has been the subject of extensive studies in recent years, particularly in the field of refrigeration where it is at the heart of research to replace CFC and HCFC. Its ther... The use of carbon dioxide as a working fluid has been the subject of extensive studies in recent years, particularly in the field of refrigeration where it is at the heart of research to replace CFC and HCFC. Its thermodynamic properties make it a fluid of choice in the efficient use of energy at low and medium temperatures in engine cycles. However, the performance of transcritical CO2 cycles weakens under high temperature and pressure conditions, especially in refrigeration systems;On the other hand, this disadvantage becomes rather interesting in engine cycles where CO2 can be used as an alternative to the organic working fluid in small and medium-sized electrical systems for low quality or waste heat sources. In order to improve the performance of systems operating with CO2 in the field of refrigeration and electricity production, research has made it possible to develop several concepts, of which this article deals with a review of the state of the art, followed by analyzes in-depth and critical of the various developments to the most recent modifications in these fields. Detailed discussions on the performance and technical characteristics of the different evolutions are also highlighted as well as the factors affecting the overall performance of the systems studied. Finally, perspectives on the future development of the use of CO2 in these different cycles are presented. 展开更多
关键词 Refrigeration Cycle Power Cycle System Performance Transcritical CO2 Cycles Working Fluid
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A New Experimental Rig of Testing Flow Boiling Heat Transfer of Refrigerantand Lubricant Mixture 被引量:5
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作者 魏文建 丁国良 王凯建 《Journal of Shanghai Jiaotong university(Science)》 EI 2004年第4期62-67,共6页
This paper proposed a new experimental rig of testing flow boiling heat transfer of refrigerant and lubricant oil mixture. The quantity of oil in the test section can be controlled and regulated conveniently and accur... This paper proposed a new experimental rig of testing flow boiling heat transfer of refrigerant and lubricant oil mixture. The quantity of oil in the test section can be controlled and regulated conveniently and accurately by connecting separate lubricant oil circuit with test section in parallel. It was built up by retrofitting a multiple air-conditioner and installing three oil-separators in serials at the compressor outlet. And so the lubricant oil in the discharged refrigerant gas of compressor can be removed completely.The refrigerant flow rate through test section can be bypassed by the by-path circuit of indoor unit.This experimental rig has advantages such as on-line and continuous oil injection, short time of obtaining stability, flexible operation, simple control, which lead to high efficiency in the research of flow boiling heat transfer of refrigerant and lubricant oil mixture. 展开更多
关键词 refrigerant flow boiling heat transfer lubricant oil
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Mixed refrigerant composition shift due to throttle valves opening in auto cascade refrigeration system 被引量:5
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作者 许雄文 刘金平 曹乐 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第1期199-204,共6页
Auto cascade refrigeration(ACR) cycle with phase separators is widely used in the cryogenic system. The composition of mixed refrigerant has a great effect on the performance of the system. Based on the assumption of ... Auto cascade refrigeration(ACR) cycle with phase separators is widely used in the cryogenic system. The composition of mixed refrigerant has a great effect on the performance of the system. Based on the assumption of infinite volume of phase separator, ACR system with one phase separator is simulated in this paper. The variation of refrigerant composition under different valves opening is obtained. A related experimental system is set up to verify the variation. The result shows that when the valve opening connected to the evaporator increases or the valve opening under the phase separator decreases, the low-boiling component concentration of the working mixture passing through the compressor and condenser increases, while the high-boiling component concentration decreases. Furthermore, the variations of condensation pressure and evaporation pressure under different valves opening are also observed. This paper is helpful to deepen the understanding of ACR system. 展开更多
关键词 Auto cascade REFRIGERATION Composition shift THROTTLE
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Experimental Analysis of the Performances of Unit Refrigeration Systems Based on Parallel Compressors with Consideration of the Volumetric and Isentropic Efficiency 被引量:8
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作者 Daoming Shen Chao Gui +1 位作者 Jinhong Xia Songtao Xue 《Fluid Dynamics & Materials Processing》 EI 2020年第3期489-500,共12页
The performances of a refrigeration unit relying on compressors working in parallel have been investigated considering the influence of the compressor volumetric efficiency and isentropic efficiency on the compression... The performances of a refrigeration unit relying on compressors working in parallel have been investigated considering the influence of the compressor volumetric efficiency and isentropic efficiency on the compression ratio.Moreover,the following influential factors have been taken into account:evaporation temperature,condensation temperature and compressor suction-exhaust pressure ratio for different opening conditions of the compressor.The following quantities have been selected as the unit performance measurement indicators:refrigeration capacity,energy efficiency ratio(COP),compressor power consumption,and refrigerant flow rate.The experimental results indicate that the system refrigeration capacity and COP decrease with a decrease in evaporation temperature,increase of condensation temperature,and increase in pressure ratio.The refrigerant flow rate increases with the increase in evaporation temperature,decrease in condensing temperature and increase in pressure ratio.The compressor power consumption increases with the increase in condensing temperature and increase in pressure ratio,but is not significantly affected by the evaporation temperature. 展开更多
关键词 Parallel compressor unit evaporation temperature condensation temperature pressure ratio refrigeration capacity energy efficiency ratio(COP)
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Experimental Performance of Moderate and High Temperature Heat Pump Charged with Refrigerant Mixture BY-3 被引量:3
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作者 陈成敏 张于峰 +4 位作者 邓娜 马洪亭 张彦所 马丽筠 胡晓微 《Transactions of Tianjin University》 EI CAS 2011年第5期386-390,共5页
Theoretical and experimental analysis of a new refrigerant mixture BY-3 was conducted based on a single-stage vapor compression refrigeration system. The water-water heat pump system used BY-3 to produce hot water whe... Theoretical and experimental analysis of a new refrigerant mixture BY-3 was conducted based on a single-stage vapor compression refrigeration system. The water-water heat pump system used BY-3 to produce hot water when the low temperature was 20 ℃. The following results were obtained: the highest temperature at the condenser outlet reached about 85 ℃; when the difference between the water temperatures at the condenser outlet and the evaporator inlet was less than 40 ℃, the coefficient of performance (COP) was larger than 4; when the difference reached 55 ℃, the COP still kept 3; the discharge temperature of BY-3 was lower than 100 ℃, and the refrigerant vapor pressure kept lower than 1.8 MPa. When the water temperature at the condenser outlet reached over 85 ℃, nearly a 5 ℃ superheating temperature was maintained. 展开更多
关键词 moderate and high temperature heat pump refrigerant mixture SINGLE-STAGE compression heat pump system coefficient of performance
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Optimization of FX-70 refrigerant evaporative heat transfer and fluid flow characteristics inside the corrugated tubes using multi-objective genetic algorithm 被引量:1
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作者 Mirollah Hosseini Hamid Hassanzadeh Afrouzi +4 位作者 Sina Yarmohammadi Hossein Arasteh Davood Toghraie AJafarian Amiri Arash Karimipour 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第8期2142-2151,共10页
In this study,the heat transfer optimization(evaporation)and the specification of the FX-70 zeotropic refrigerant flow inside a corrugated pipe have been investigated.Despite the low HTC(HTC),this type of refrigerant ... In this study,the heat transfer optimization(evaporation)and the specification of the FX-70 zeotropic refrigerant flow inside a corrugated pipe have been investigated.Despite the low HTC(HTC),this type of refrigerant is highly applicable in low or medium temperature engineering systems during the evaporation process.To eliminate this defect,high turbulence and proper mixing are required.Therefore,using heat transfer(HT)augmentation methods will be necessary and effective.In order to find the most favorable operating conditions that lead to the optimum combination of pressure drop(PD)and HTC,empirical data,neural networks,and genetic algorithms(GA)for multi-objective(MO)(NSGA II)are used.To investigate the mentioned cases,the geometric parameters of corrugated pipes,vapor quality,and mass velocity of refrigerant were studied.The results showed that with vapor quality higher than 0.8 and corrugation depth and pitch of 1.5 and 7 mm,respectively,we would achieve the desired optimum design. 展开更多
关键词 OPTIMIZATION Genetic algorithm Neural network Corrugated tube FX-70 refrigerant
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Study on Application of Mixed-Refrigerant Refrigeration in Ethylene Plant 被引量:1
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作者 Zhang Wei Xu Xinru 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2009年第3期20-24,共5页
This paper focuses on the mixed-refrigerant refrigeration process flows which are applied in the cryogenic separation section of ethylene plant. Based on a 120 kt/a ethylene plant which employs a sequence separation p... This paper focuses on the mixed-refrigerant refrigeration process flows which are applied in the cryogenic separation section of ethylene plant. Based on a 120 kt/a ethylene plant which employs a sequence separation process flow and lowpressure demethanization system, the energy consumption of three refrigeration process flows(typical cascade refrigeration, binary refrigeration and tertiary refrigeration) was calculated by means of the ASPEN PLUS simulation software. An optimized mixed-refrigerant composition which achieved the minimum energy consumption of refrigeration systems was found out and the exergy loss was analyzed and compared. Results indicated that the energy consumption of typical cascade refrigeration and binary refrigeration systems was almost equal and that of tertiary refrigeration system was higher than the other two systems. Based on the current situation of production, the suggestions on production optimization and refrigeration process flow selection were put forward. 展开更多
关键词 ethylene plant mixed refrigerant REFRIGERATION EXERGY
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Magnetic entropy change of Ce6Ni2Si3-type and large refrigerant capacity GdCoSiGe compound* 被引量:1
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作者 Shen Jun Zhang Hu Wu Jian-Feng 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第2期482-486,共5页
Magnetic entropy change (△SM) and refrigerant capacity (RC) of Ce6Ni2Si3-type Gd6Co1.67Si2.5Geo.5 compounds have been investigated. The Gd6Col.67Si2.5Geo.5 undergoes a reversible second-order phase transition at ... Magnetic entropy change (△SM) and refrigerant capacity (RC) of Ce6Ni2Si3-type Gd6Co1.67Si2.5Geo.5 compounds have been investigated. The Gd6Col.67Si2.5Geo.5 undergoes a reversible second-order phase transition at the Curie temperature Tc = 296 K. The high saturation magnetization leads to a large ASM and the maximal value of △SM is found to be 5.9 J/kg. K around TC for a field change of 0-5 T. A broad distribution of the △SM peak is observed and the full width at half maximum of the △SM peak is about 101 K under a magnetic field of 5 T. The large RC is found around TC and its value is 424 J/kg. 展开更多
关键词 Gd6Col.67Si2.sGe0.5 compound magnetocaloric effect refrigerant capacity
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