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Performance Analysis of a Solar Continuous Adsorption Refrigeration System
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作者 Kolthoum Missaoui Nader Frikha +2 位作者 Abdelhamid Kheiri Slimane Gabsi Mohammed El Ganaoui 《Fluid Dynamics & Materials Processing》 EI 2023年第4期1067-1081,共15页
A study is conducted on the performances of a solar powered continuous-adsorption refrigerator considering two particular days as references cases,namely,the summer solstice(June 21st)and the autumn equinox(September ... A study is conducted on the performances of a solar powered continuous-adsorption refrigerator considering two particular days as references cases,namely,the summer solstice(June 21st)and the autumn equinox(September 21st).The cooling capacity,system performance coefficient and the daily rate of available cooling energy are assessed.The main goal is to compare the performances of a solar adsorption chiller equipped with a hot water tank(HWT)with an equivalent system relying on solar collectors with no heat storage module.The daily cooling rates for the solar refrigerator are found to be 102.4 kWh and 74.3 kWh,respectively,on June 21st and on September 21st,using a total collector’s area of 43.47 m2.The corresponding values for the adsorption chiller equipped with a hot water tank of 2 m3(and using a total collector’s area of 72.45 m2),are 127.1 kWh and 106.13 kWh,respectively. 展开更多
关键词 Solar continuous adsorption refrigerator dynamic energetic study system performance hot water tank CPC collector thorough system variable heat source
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Research of refrigeration system for a new type of constant temperature hydraulic tank 被引量:1
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作者 郭锐 Zhang Zhenmiao +2 位作者 Zhao Jingyi Ning Chao Li Bingliang 《High Technology Letters》 EI CAS 2016年第4期436-444,共9页
Different from the traditional hydraulic oil cooling method,a new type of constant temperature oil tank cooling system based on semiconductor refrigeration technology is designed. This paper studies the principle of s... Different from the traditional hydraulic oil cooling method,a new type of constant temperature oil tank cooling system based on semiconductor refrigeration technology is designed. This paper studies the principle of semiconductor refrigeration and establishes a heat transfer model. Semiconductor cooler on piping refrigeration is simulated,and influence of the parameters on the outlet temperature,such as pipe pressure difference of inlet and outlet,pipe length,pipe radius,are gotten,and then hydraulic tank semiconductor refrigeration system is proposed. The semiconductor refrigeration system can control temperature at 37 ± 1°C. 展开更多
关键词 refrigeration system constant temperature control semiconductor refrigeration technology hydraulic tank simulated analysis experimental study
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Refrigeration system synthesis based on de-redundant model by particle swarm optimization algorithm
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作者 Danlei Chen Yiqing Luo Xigang Yuan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第10期412-422,共11页
Simultaneous optimization of refrigeration system(RS)and its heat exchanger network(HEN)leads to a large-scale non-convex mixed-integer non-linear programming(MINLP)problem.Conventionally,researchers usually adopted s... Simultaneous optimization of refrigeration system(RS)and its heat exchanger network(HEN)leads to a large-scale non-convex mixed-integer non-linear programming(MINLP)problem.Conventionally,researchers usually adopted simplifications to confine problem scale from being too large at the cost of reducing solution space.This study established an optimization framework for the simultaneous optimization of RS and HEN.Firstly,A more comprehensive and compact model was developed to guarantee a relatively complete solution space while reducing model scale as well as its solving difficulty.In this model,a tandem arrangement of connecting sub-coolers and expansion valves was considered in the superstructure;and the pressure/temperature levels were optimized as continuous variables.On this basis,we proposed a"two-step transformation method"to equivalently transform the cross-level structure into a no n-cross-level structu re,and the de-redundant superstructu re was established with ensuring comprehensiveness and rigor.Furthermore,the MINLP model was developed and solved by Particle Swarm Optimization algorithm.Finally,our methodology was validated to get better optimal results with less CPU time in two case studies,an ethylene RS in an existing plant and a reported propylene RS. 展开更多
关键词 refrigeration system Optimal design Process systems Particle swarmoptimization Mathematical modeling
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EXPERIMENTAL INVESTIGATION ON R134A AIRBORNE VAPOR-COMPRESSION REFRIGERATION SYSTEM
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作者 李运祥 潘泉 刘娟 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2013年第1期46-52,共7页
The airborne high power electrical equipments have been widely used in modern aircrafts , which consequently causes the dramatic increase of heating load up to dozens of kilowatts.Accordingly , vapor-compression refri... The airborne high power electrical equipments have been widely used in modern aircrafts , which consequently causes the dramatic increase of heating load up to dozens of kilowatts.Accordingly , vapor-compression refrigeration system ( VCRS ) with lower engine bleed air and larger refrigeration capacity has been paid much attention in recent years.Therefore , based on the analysis of the characteristics of VCRS , an experiment system of VCRS using R134ais set up to simulate operation performances.The influences of different parameters including evaporation pressure , condensing pressure , refrigerant mass flow rate and compressor rotation speed are also investigated.The impacts of different parameters on the system performance are various.This work can help to establish the specific control law under different work conditions. 展开更多
关键词 vapor-compression refrigeration system fighter plane R134A experimental investigation
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Experiments on an Open-Loop Cycle Carbon Dioxide Refrigeration System
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作者 徐雷 蒋彦龙 +1 位作者 郑小漪 蔡玉飞 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2015年第4期452-460,共9页
An open loop cycle carbon dioxide(CO2)refrigeration system is established,and the cooling performances of high-pressure CO2 under different storage conditions(25℃,30℃,and 35℃)are investigated.Moreover,the experimen... An open loop cycle carbon dioxide(CO2)refrigeration system is established,and the cooling performances of high-pressure CO2 under different storage conditions(25℃,30℃,and 35℃)are investigated.Moreover,the experimental mass flow rates of CO2 are compared with the theoretical values at different conditions and refrigeration capacities.The results indicate that the storage condition of CO2 has a significant impact on the refrigeration performance,and the mass flow rate of CO2 increases with the increasing storage temperature in a given refrigeration capacity. 展开更多
关键词 CO2 open loop cycle refrigeration system mass flow rate storage condition
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CFD Analysis of the Influence of Ionic Liquids on the Performances of a Refrigeration System
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作者 Jianghao Niu 《Fluid Dynamics & Materials Processing》 EI 2021年第6期1003-1013,共11页
The falling film of an ionic liquid([EMIM][DMP]+H_(2)O)and its effect on a refrigeration system are numerically simulated in the framework of a Volume of Fluid(VOF)method(as available in the ANSYS Fluent computational... The falling film of an ionic liquid([EMIM][DMP]+H_(2)O)and its effect on a refrigeration system are numerically simulated in the framework of a Volume of Fluid(VOF)method(as available in the ANSYS Fluent computational platform).The properties of the liquid film and the wall shear stress(WSS)are compared with those obtained for a potassium bromide solution.Different working conditions are considered.It is noted that the ionic liquid demonstrates a better absorption capability,with a coefficient of performance(COP)of 0.55.It is proved that the[EMIM][DMP]+H_(2)O ionic liquid working substance is superior to the potassium bromide solution in terms of heat and mass transfer. 展开更多
关键词 Ionic liquid fluent simulation [EMIM][DMP]+H_(2)O absorption refrigeration system
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Development of Environmentally Friendly and Energy Efficient Refrigerants for Refrigeration Systems
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作者 Piyanut Saengsikhiao Juntakan Taweekun +2 位作者 Kittinan Maliwan Somchai Sae-ung Thanansak Theppaya 《Energy Engineering》 EI 2021年第2期411-433,共23页
This paper presents the improvement of eco-friendly and power consumption saving refrigerants for refrigeration systems.The novel azeotropic refrigerant mixtures of HFCs and HCs can replace refrigeration systems,and u... This paper presents the improvement of eco-friendly and power consumption saving refrigerants for refrigeration systems.The novel azeotropic refrigerant mixtures of HFCs and HCs can replace refrigeration systems,and using the R134,R32,R125,and R1270 refrigerants in several compositions found using the decision tree function of the RapidMiner software(which camefirst in the KDnuggets annual software poll).All refrigerant results are mixed of POE,which is A1 classification refrigerant,non-flammable,and innocuous refrigerant,and using REFPROP software and CYCLE_D-HX software are under the CAN/ANSI/AHRI540 standards.The boiling point of the new refrigerant mix R-No.595 is 4.58%,lower than that of R404A,with a higher refrigerant effect and 50.34%lower GWP value than R404A.The proposed mix R-No.595 can be operated in hot environmental country and has high critical temperature and heat-rejection effects,due to the presence of R32 and R1270.The COPc of R463A is 13.49%,higher than R404A in freeze condition.The novel refrigerant mixes provide alternate refrig-erant options mixed of 1%R1270,and which are related with the development of current refrigerants,containing a compose of HFOs and eco refrigerants for producing low-GWP,zero ODP,high-refrigerant effect,low-operating pressure,and innocuous refrigerants. 展开更多
关键词 REFRIGERANT refrigeration system energy efficiency environmentally friendly data mining
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Improving the Thermal Efficiency and Performance of Refrigeration Systems:Numerical-Experimental Analysis of Minimization of Frost Formation
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作者 Felipe Mercês Biglia Raquel da Cunha Ribeiro da Silva +2 位作者 Fátima deMoraes Lino Kamal Abdel Radi Ismail Thiago Antonini Alves 《Energy Engineering》 EI 2022年第5期1771-1788,共18页
The frost growth on cold surfaces in evaporators is an undesirable phenomenon which becomes a problem for the thermal efficiency of the refrigeration systems because the ice layer acts as a thermal insulation,drastica... The frost growth on cold surfaces in evaporators is an undesirable phenomenon which becomes a problem for the thermal efficiency of the refrigeration systems because the ice layer acts as a thermal insulation,drastically reducing the rate of heat transfer in the system.Its accumulation implies an increase in energy demand and a decrease in the performance of various components involved in the refrigeration process,reducing its efficiency and making it necessary to periodically remove the frost,resulting in expenses for the defrost process.In the present work,a numerical-experimental analysis was performed in order to understand the formation process of porous ice in flat plates with different surface treatments and parameters.This understanding is of utmost importance to minimize the formation of porous ice on cold surfaces and improve equipment efficiency and performance.In this context,a low-cost experimental apparatus was developed,enabling an experimental analysis of the phenomenon under study.The environmental conditions evaluated are the temperature of the cold surface,roomtemperature,humidity,and air velocity.The material of the surfaces under study are aluminum,copper,and brass with different surface finishes,designated as smooth,grooved(hydrophilic),and varnished(hydrophobic).The numerical-experimental analysis demonstrates measurements and simulations of the thickness,surface temperature,and growth rate of the porous ice layer as a function of the elapsed time.The numerical results were in good agreement with the experimental results,indicating that the varnished surface,with hydrophobic characteristics,presents greater difficulty in providing the phenomenon.Therefore,the results showed that application of a coating allowed a significant reduction on the frost formation process contributing to the improvement of thermal efficiency and performance of refrigeration systems. 展开更多
关键词 Frost layer growth frost thickness minimization of frost hydrophobic surface refrigeration systems
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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:4
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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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Exergy Analysis of a Double-Effect Solar Absorption Refrigeration System in Ngaoundere 被引量:1
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作者 Maurice Tenkeng Paiguy Armand Ngouateu Wouagfack Réné Tchinda 《World Journal of Engineering and Technology》 2019年第1期158-174,共17页
Solar energy is replacing more and more traditional sources of energy because of the fact that it’s also fighting about global warming. This study is based on exergy analysis of a double-effect series flow absorption... Solar energy is replacing more and more traditional sources of energy because of the fact that it’s also fighting about global warming. This study is based on exergy analysis of a double-effect series flow absorption refrigeration system powered by solar energy in Ngaoundere. The simulation is done on the basis of a half hourly analysis for the first time, from 6.30 AM to 6.30 PM, using water-lithium bromide as working pair. The main parameters for the performance of an absorption cycle, which are the COP and the ECOP, have been analyzed and the results show that this two parameters increase while increasing the temperature of the main generator. The exergy loss of each component of the system and the total exergy loss of the system have been analyzed and their effectiveness calculated, using the first and second law of thermodynamics. The highest exergy loss occurs in the main generator GI and in the absorber, making these components more important in an absorption cycle. This analysis is based on a mathematical model using FORTRAN?language. The results obtained may be useful for the optimization of solar absorption refrigeration systems. 展开更多
关键词 DOUBLE Effect refrigeration HALF Hourly EXERGY LOSS
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Thermodynamic Calculation and Analysis of Biomass Energy Applied in the NH_3/He Absorption Refrigeration System 被引量:2
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作者 ZHAO Qing-ling CHEN Fu-jin +1 位作者 GUO Yu-jie ZHAO Ting-lin 《Meteorological and Environmental Research》 2012年第7期5-7,11,共4页
[Objective] The study aimed to discuss the factors influencing the application of shaping biomass energy in the NHJHe absorption re- frigeration system. [ Method] In the NHJHe absorption refrigeration system, the ther... [Objective] The study aimed to discuss the factors influencing the application of shaping biomass energy in the NHJHe absorption re- frigeration system. [ Method] In the NHJHe absorption refrigeration system, the thermodynamic analysis of semi-gasification furnace based on sec- tional combustion technology and absorption refrigeration system was performed. [ Result] Biomass could burn cleanly and efficiently in the semi- gasification furnace, which can reduce the environmental pollution caused by the combustion of coal and other fossil fuels. The heating power of the furnace for the absorption refrigeration system could not be too high, so biomass energy and other low-grade energy can be used as heat sources, which opens up a new way for the utilization of biomass energy. [ Conclusion] Biomass energy was applied successfully in the absorption refrigera- tion system. 展开更多
关键词 Biomass energy NHJHe absorption-diffusion refrigeration Thermodynamic analysis China
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Entropy Analysis of Vapor-Compression Refrigeration System by Using the Second Law of Thermodynamics
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作者 杨洪海 《Journal of China Textile University(English Edition)》 EI CAS 1999年第4期42-44,共3页
By means of the Second Law of Thermodynamics,thispaper gives out the entropy analysis method for vapor-comperession refrigeration system.The thermal irrevers-ibility of the system charged with R12 and its hopeful al-t... By means of the Second Law of Thermodynamics,thispaper gives out the entropy analysis method for vapor-comperession refrigeration system.The thermal irrevers-ibility of the system charged with R12 and its hopeful al-ternative refrlgerant R134a have been studied respective-ly.On the basis of all the research results of this paper,the measure used to save energy for vapor-compressionrefrigeration system has been put out. 展开更多
关键词 Vapor - Compression refrigeration system Sec-ond Law of THERMODYNAMICS ENTROPY ANALYSIS Alternative REFRIGERANT of CFC’s
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A DYNAMIC MODEL OF THE SOLAR-POWERED SOLID ABSORPTION REFRIGERATION SYSTEM
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作者 Lin Guiping Mei Zhiguang(Faculty 505, Beijing University of Aeronautics andAstronautics, Beijing, China, 100083) 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 1995年第3期174-178,共5页
A dynamic model is established for the solar-powered solid-absorptionrefrigeration system using CaCl2 and NH3 as working pair. The reaction front assump-tion is taken to calculate the heat transfer process in this mo... A dynamic model is established for the solar-powered solid-absorptionrefrigeration system using CaCl2 and NH3 as working pair. The reaction front assump-tion is taken to calculate the heat transfer process in this model. This assumption as-sumes that des 展开更多
关键词 SOLAR energy refrigerating MACHINERY DYNAMIC MODELS calciumchlorides. AMMONIA
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Magnetic Field Enhancement in Ammonia-Water Absorption Refrigeration Systems
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作者 Moradeyo K. Odunfa Richard O. Fagbenle +1 位作者 Olanrewaju M. Oyewola Olayinka S. Ohunakin 《Energy and Power Engineering》 2014年第4期54-68,共15页
Absorption enhancement has been considered as an effective way of improving coefficient of performance (COP) of refrigeration systems and magnetic enhancement is one of these methods. A model of magnetic field enhance... Absorption enhancement has been considered as an effective way of improving coefficient of performance (COP) of refrigeration systems and magnetic enhancement is one of these methods. A model of magnetic field enhancement in ammonia-water absorption systems is presented in this paper. A numerical model using finite difference scheme was developed based on the conservation equations and mass transport relationship. Macroscopic magnetic field force was introduced in the momentum equation. The model was validated using data obtained from the literature. Changes in the physical properties of ammonia solution while absorbing both in the direction of falling film and across its thickness were investigated. The magnetic field was found to have some positive effect on the ammonia-water falling film absorption. The results indicate that absorption performance enhancement increased with magnetic intensity. The COP of simple ammonia solution absorption refrigeration system increased by 1.9% and 3.6% for magnetic induction of 1.4 and 3.0 Tesla respectively. 展开更多
关键词 AMMONIA-WATER Absorption refrigeration Magnetic Field Force AMMONIA SOLUTION Concentration COEFFICIENT of Performance Finite Difference Scheme Numerical SOLUTION
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Exergy Analysis of a Solar Absorption Refrigeration System in Ngaoundere
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作者 Maurice Tenkeng Paiguy Armand Ngouateu Wouagfack +1 位作者 Daniel Lissouck Réné Tchinda 《Journal of Power and Energy Engineering》 2017年第10期1-18,共18页
In this study, the first and second laws of thermodynamics are used to analyze the performance of a single-stage absorption refrigeration system powered by solar energy. The working pair used in this study is LiBr-H2O... In this study, the first and second laws of thermodynamics are used to analyze the performance of a single-stage absorption refrigeration system powered by solar energy. The working pair used in this study is LiBr-H2O where water (H2O) is the refrigerant and the lithium bromide (LiBr) is the absorbent. A mathematical model based on exergy analysis is applied to analyse the system performance. Temperature, enthalpy, entropy, mass flow rate and exergy loss of each component including evacuated tube solar collector are evaluated. Furthermore, the overall coefficient of performance (COPcooling) and the overall exergetic coefficient of performance (ECOPcooling) of the solar absorption system (absorption system coupled to an evacuated tube solar collector) for cooling purpose are calculated from the thermodynamic properties of the working fluids under weather conditions of Ngaoundere city, Cameroon. The calculations were done on the basis of a half hourly analysis from 6:30 AM to 6:30 PM. The results were compared and they show that the exergy destruction highly occurs in the generator and the solar collector. The simulation results can be used for the thermodynamics optimization of solar absorption refrigeration systems. 展开更多
关键词 refrigeration ABSORPTION EXERGY Analysis SOLAR COLLECTOR
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Experimental Study on Ice Slurry Refrigeration System with Pre-Cooling Heat Exchanger
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作者 Xukai Yang Shengchun Liu 《Engineering(科研)》 2015年第5期230-236,共7页
In the present study, the ice slurry refrigeration system with pre-cooling heat exchanger (ISSH) is studied experimentally to achieve the system performance, ice crystal formation time and the temperature of ice cryst... In the present study, the ice slurry refrigeration system with pre-cooling heat exchanger (ISSH) is studied experimentally to achieve the system performance, ice crystal formation time and the temperature of ice crystal formation. The operating parameters considered in this paper include the concentration of salt solution, suction pressure, discharge pressure and Energy Efficiency Ratio (EER). The result shows that the temperature of critical time of ice crystal formation decreases with the increasing concentration of salt solution and that the ice crystal formation time increases with the increasing concentration of salt solution. In the same concentration of salt solution, the ice crystal formation temperature of ISSH is lower than that of basic ice slurry refrigeration system (BISS), and the ice crystal formation time of ISSH is shorter than that of BISS. On the whole, the EER of ice slurry refrigeration system with pre-cooling heat exchanger is higher than that of basic ice slurry refrigeration system. 展开更多
关键词 Ice SLURRY refrigeration system PRE-COOLING Heat EXCHANGER EER
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Performance of an Activated Carbon-Ammonia Adsorption Refrigeration System
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作者 Tao Zeng Hongyu Huang +1 位作者 Noriyuki Kobayashi Jun Li 《Natural Resources》 2017年第10期611-631,共21页
An experimental study of the adsorption performances of NH3 on several commercial activated carbons was described. Firstly, the specific surface area, pore size distribution and morphological structure of the activate... An experimental study of the adsorption performances of NH3 on several commercial activated carbons was described. Firstly, the specific surface area, pore size distribution and morphological structure of the activated carbons have been characterized by N2 adsorption, Scanning Electron Microscope (SEM), and X-ray diffraction (XRD). The adsorption capacities of four kinds of activated carbons were compared based on adsorption isotherms at 30℃. Results show that a type of activated carbon MSC30 with high adsorption capacity of NH3 is a promising adsorbent for NH3 because of its large specific surface area and high pore volume. Secondly, the effect of adsorption temperature on the adsorption capacity of NH3 on MSC30 was investigated. A modified Dubinin-Astakhov equation was employed to describe the adsorption isotherms, with the reliability and accuracy evaluation. The isosteric heat of adsorption of MSC30-NH3 as a function of the amount adsorbed was calculated applying the Clausius-Clapeyron equation with isotherms obtained at 20℃ and 30℃. Thirdly, a packed-bed type adsorber was used to evaluate the influence of cycle time on the system cooling performance (coefficient of performance, specific cooling performance, and volumetric cooling performance) of the MSC30-NH3 pair at the evaporating temperatures of 5℃, 10℃ and 15℃ with a fixed adsorption/condensing temperature and desorption temperature of 30?C and 80℃, respectively. Finally, a long term operation without degradation for MSC30-NH3 adsorption was experimentally demonstrated from the 80 consecutive adsorption-desorption cycles. 展开更多
关键词 ADSORPTION refrigeration AMMONIA ACTIVATED Carbon ADSORPTION ISOTHERM ADSORPTION Characteristics
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Plastic Crystal Neopentyl Glycol/Multiwall Carbon Nanotubes Composites for Highly Efficient Barocaloric Refrigeration System
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作者 DAI Zhaofeng SHE Xiaohui +5 位作者 SHAO Bohan YIN Ershuai DING Yulong LI Yongliang ZHANG Xiaosong ZHAO Dongliang 《Journal of Thermal Science》 SCIE EI CSCD 2024年第1期383-393,共11页
Plastic crystal neopentyl glycol(NPG)exhibits colossal barocaloric effect with high entropy changes.However,their application is restricted in several aspects,such as low thermal conductivity,substantial supercooling ... Plastic crystal neopentyl glycol(NPG)exhibits colossal barocaloric effect with high entropy changes.However,their application is restricted in several aspects,such as low thermal conductivity,substantial supercooling effect,and poor springback properties.In this work,multi-walled carbon nanotubes(MWCNTs)with ultra-high thermal conductivity and high mechanical strength were selected for performance enhancement of NPG.The optimal mixing ratio was determined to be NPG with 3 wt%MWCNTs composites,which showed a 6K reduction in supercooling without affecting the phase change enthalpy.Subsequently,comprehensive performance of the composites with optimal mixing ratio was compared with pure NPG At 40 MPa,390J·K^(-1)·kg^(-1)change in entropy and 9.9 K change in temperature were observed.Furthermore,the minimum driving pressure required to achieve reversible barocaloric effect was reduced by 19.2%.In addition,the thermal conductivity of the composite was increased by approximately 28%,significantly reducing the heat exchange time during a barocaloric refrigeration cycle.More importantly,ultra-high pressure release rate resulted in a73.7%reduction in the springback time of the composites,offering new opportunities for the recovery of expansion work. 展开更多
关键词 barocaloric refrigeration neopentyl glycol MWCNTS performance enhancement
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Thermodynamic Analysis on the Performance of Barocaloric Refrigeration Systems Using Neopentyl Glycol as the Refrigerant 被引量:2
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作者 DAI Zhaofeng SHE Xiaohui +3 位作者 WANG Chen DING Yulong ZHANG Xiaosong ZHAO Dongliang 《Journal of Thermal Science》 SCIE EI CAS CSCD 2023年第3期1063-1073,共11页
Barocaloric refrigeration is regarded as one of the next-generation alternative refrigeration technology due to its environmental friendliness.In recent years,many researchers have been devoted to finding materials wi... Barocaloric refrigeration is regarded as one of the next-generation alternative refrigeration technology due to its environmental friendliness.In recent years,many researchers have been devoted to finding materials with colossal barocaloric effects,while neglecting the research on barocaloric refrigeration devices and thermodynamic cycles.Neopentyl glycol is regarded as one of the potential refrigerants for barocaloric refrigeration due to its giant isothermal entropy changes and relatively low operating pressure.To evaluate the performance of the barocaloric system using Neopentyl glycol,for the first time,this study establishes a thermodynamic cycle based on the metastable temperature-entropy diagram.The performance of the proposed system is investigated from the aspects of irreversibility,operating temperature range,and operating pressure,and optimized with finite-rate heat transfer.The guidance for the optimal design of the system is given by revealing the effect of the irreversibility in two isobaric processes.The results show that a COP of 8.8 can be achieved at a temperature span of 10 K when the system fully uses the phase transition region of Neopentyl glycol,while a COP of 3 can be achieved at a temperature span of 10 K when the system operates at room temperature.Furthermore,this study also shows that the system performance can be further improved through the modification of Neopentyl glycol,and some future development guidance is provided. 展开更多
关键词 barocaloric refrigeration neopentyl glycol thermodynamic analysis COP refrigeration capacity
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An Application of Nonlinear Autoregressive(NARX)Model to Predict Adsorbent Bed Temperature of Solar Adsorption Refrigeration System
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作者 Fatih Bouzeffour Benyoucef Khelidj 《Journal of Systems Science and Systems Engineering》 SCIE EI CSCD 2023年第6期687-707,共21页
In any solar adsorption refrigeration system,there are three major components:a solar collector adsorbent bed,a condenser and an evaporator.All of those components operate at different temperature levels.A solar colle... In any solar adsorption refrigeration system,there are three major components:a solar collector adsorbent bed,a condenser and an evaporator.All of those components operate at different temperature levels.A solar collector with a tubular adsorbent configuration is proposed and numerically investigated.In this study,a nonlinear auto-regressive model with exogenous input is applied for the prediction of adsorbent bed temperature during the heating and desorption period.The developed neuronal model uses the MATLAB Network toolbox to obtain a better configuration network,applying multilayer feed-forward,the TANSIG transfer function,and the back-propagation learning algorithm.The input parameters are ambient temperature and the uncontrolled natural factor of solar radiation.The output network contains a variable representing the adsorbent bed temperature.The values obtained from the network model were compared with the experimental data,and the prediction performance of the network model was examined using various performance parameters.The mean square error(MSE)and the statistical coefficient of determination(R2)values are excellent numerical criteria for evaluating the performance of a prediction tool.A well-trained neural network model produces small MSE and higher R2 values.In the current study,the adsorbent bed temperature results obtained from a neural network with a two neuron in hidden layer and the number of the tapped time-delays d=9 provided a reasonable degree of accuracy:MSE=1.0121 and R2=0.99864 and the index of agreement was 0.9988.This network model,based on a high-performance algorithm,provided reliable and high-precision results concerning the predictable temperature of the adsorbent bed. 展开更多
关键词 Artificial neural networks NARX solar collector adsorption refrigerator adsorbent bed temperature
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