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Performance of a single-stage auto-cascade refrigerator operating with a rectifying column at the temperature level of -60°C

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第2期12卷 139-145页

作者： Qin WANG Kang CUI Teng-fei SUN Guang-ming CHEN Institute of Refrigeration and Cryogenics State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 310027 China

This paper proposes a new approach to the performance optimization of an auto-cascade refrigerator(ACR) operating with a rectifying column and six types of binary refrigerants(R23/R134a,R23/R227ea,R23/R236fa,R170/R290,R170/R600a,and R170/R600) at a temperature level of -60 °C. Half of the six binary refrigerants are nonflammable,of which the 0.5 and the 0.6 mole fractions of R23 for the R23/R236fa possess the most prospective composition for the medium and low suction pressure compressors,respectively. The remaining three binary refrigerants are flammable but with low global warming potentials,of which the 0.6 mole fraction of R170 for the R170/R600 is the most prospective one. The results show that the overall matching as well as local matching of heat capacity rates of hot and cold refrigerants in the recuperators are important for the improvement of coefficient of performance of the cycle,which can be adjusted through the simultaneous optimization of the pressure level and composition. The new approach proposed also offers a wider range of applications to the optimization in performance of the cycle using multi-component refrigerants.

关键词： Auto-cascade Binary refrigerant refrigerator Optimization

Performance of a single-stage Linde-Hampson refrigerator operating with binary refrigerants at the temperature level of-60°C

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第2期11卷 115-127页

作者： Qin WANG Kang CUI Teng-fei SUN Fu-sheng CHEN Guang-ming CHEN State Key Laboratory of Clean Energy Utilization Institute of Refrigeration and Cryogenics Zhejiang University Hangzhou 310027 China

The optimization of the performance of a single-stage Linde-Hampson refrigerator （LHR） operating with six different binary refrigerants （R23/R134a, R23/R227ea, R23/R236ea, R170/R290, R170/R600a and R170/R600） with ozone depletion potentials （ODPs） of zero was conducted using a new approach at the temperature level of-60℃. Among these binary refrig- erants, the 0.55 and the 0.6 mole fractions of R23 for R23/R236ea are the most prospective nonflammable ones for the medium and low suction pressure compressors, respectively. For these two kinds of compressors, the 0.6 and the 0.65 mole fractions of R170 for R 170/R600, respectively, are the most prospective binary refrigerants with low global warming potentials （GWPs）. The results of optimization of pressure levels indicate that the optimum low pressure value for coefficients of performance （COP） is achieved when the minimum temperature differences occur at both the hot and the cold ends of the recuperator at a specified composition and pressure ratio. Two useful new parameters, the entropy production per unit heat recuperated and the ratio of heat recuperating capacity to the power consumption of the compression, were introduced to analyze the exergy loss ratio in the recuperator. The new approach employed in this paper also suggests a promising application even to the optimization of the performance with multi-component refrigerants.

关键词： Linde-Hampson Binary refrigerant refrigerator Performance Optimization

A Nanosize Quantum-Dot Photoelectric refrigerator

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Chinese Physics Letters 2013年第8期30卷 38-41页

作者： LI Cong ZHANG Yan-Chao HE Ji-Zhou Department of Physics Nanchang UniversityNanchang 330031

We investigate the thermodynamic performance of a nanosized photoelectric refrigerator consisting of two single energy levels embedded between two reservoirs at different *** on the quantum master equation,expressions for the cooling power and coefficient of performance(COP)of the refrigerator are *** characteristic curves between the cooling power and COP are ***,the optimal performance parameters are analyzed by the numerical calculation and graphic *** influence of the nonradiative processes on the performance characteristics and optimal performance parameters are discussed in detail.

关键词： refrigerator optimal performance

The Performance Characteristics of a Nano-thermoelectric refrigerator Driven by an External Stochastic Force

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Chinese Physics Letters 2013年第5期30卷 135-139页

作者： WANG Hao WU Guo-Xing Tianhua College Shanghai Normal UniversityShanghai 201815

We describe a single level quantum dot driven by an external stochastic force which works as a nano-thermoelectric refrigerator. Based on the model, expressions for the cooling rate, power input, and coefficient of performance (COP) are derived. The effects of the energy level and energy space on the refrigerator are revealed. The optimal performance characteristics are analyzed by numerical calculation. Furthermore, the practical operating regions of the refrigerator are determined.

关键词： refrigerator calculation stochastic

Process Modeling and Control Simulation for a 500W@4.5K Helium refrigerator

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Journal of Harbin Institute of Technology(New Series) 2016年第4期23卷 15-21页

作者： Xiaofei Lu Zhiwei Zhou Ming Zhuang Lilong Qiu Institute of Plasma Physics Chinese Academy of Sciences

In order to investigate dynamic behaviors of a 500W@ 4.5K helium refrigerator,the process simulator has been completed. The cryogenic process model is described and main components are customized. The realtime communication between the process model and the control system has been achieved. Compared with the preliminary experimental data,the errors of temperatures during the process of 300 K-80 K are less than 10%.The process model is validated to predict the cool-down process very well. The controller parameters are tuned in simulation and applied to the actual refrigerator suitably. Based on the dynamic simulation,the operation of Joule-Thomson( JT) by pass valve has been optimized. And the cool- down process from 300 K to 4. 5 K has been simulated under the control programs. Simulation results indicate that this dynamic simulator based on actual control architecture is available to process control and operation optimization for the helium refrigerators.

关键词： Helium refrigerator process simulation controller tuning operation optimization virtual commissioning

Coefficient of Performance at Maximum χ-Criterion for Feynman Ratchet as a refrigerator

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Communications in Theoretical Physics 2014年第10期61卷 589-595页

作者：盛世奇杨盼涂展春 Department of Physics Beijing Normal University Kavli Institute for Theoretical Physics China the Chinese Academy of Sciences

The χ-criterion is defined as the product of the energy conversion efficiency and the heat absorbed per unit time by the working substance [de Tom′as et al., Phys. Rev. E 85(2012) 010104(R)]. The χ-criterion for Feynman ratchet as a refrigerator operating between two heat baths is optimized. Asymptotic solutions of the coefficient of performance at maximum χ-criterion for Feynman ratchet are investigated at both large and small temperature difference. An interpolation formula, which fits the numerical solution very well, is proposed. Besides, the sufficient condition for the universality of the coefficient of performance at maximum χ is investigated.

关键词： Feynman ratchet refrigerator coefficient of performance χ-criterion universal COP

refrigerator Coupling to a Water-Heater and Heating Floor to Save Energy and to Reduce Carbon Emissions

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Computational Water, Energy, and Environmental Engineering 2013年第1期2卷 21-29页

作者： Romdhane Ben Slama ISSAT Gabes Rue Omar Ibn Khattab Gabes Tunisia

With an aim of rationing use of energy, energy safety, and to reduce carbon emission, our interest was geared towards the refrigerators and all the refrigerating machines. Indeed the heat yielded by the exchanger condenser can be developed for the water heating, floors heating etc. After an encouraging theoretical study, two prototypes were produced in order to validate the theoretical results. A first refrigerator was coupled with a water-heater and another with a heating floor. The water temperature reached, in one day, is of 60℃;which makes it possible to predict better results with a continuously used refrigerator. In the same way for the heating floor coupled with the second refrigerator, the temperature reached high values because the surface is reduced;however for the heating floors the standard fixes the temperature between 28℃ and 30℃.

关键词： refrigerator Recuperator Heating Water Heating Floor Heat Pump

Life Cycle Input-Output Analysis Extended to Use, Disposal, and Recycling Stages Applied to Embodied CO2 Emissions of a refrigerator

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Journal of Energy and Power Engineering 2013年第4期7卷 695-704页

作者： Yuki Mizumoto Yohji Uchiyama Keiichi Okajima Department of Risk Engineering Graduate School of System and Information Engineering University of Tsukuba lbaraki305-8537 Japan Department of Risk Engineering Faculty of System and Information Engineering University of Tsukuba Ibaraki 305-8537 Japan

Input-output analysis is widely employed to analyze inventories of a product＇s embodied energy and environmental burdens. However, input-output analysis focuses only on the production stage and ignores other life cycle phases. Input-output analysis is not exactly a LCA （life cycle assessment） method in the strict sense of ISO 14040 standards, which must cover all stages of a product＇s life cycle, ＂from the cradle to the grave＂, so to speak. A tiered hybrid LCA is a useful tool that covers all life cycle stages by combining a process analysis with the input-output analysis method. This study aims to extend input-output analysis to the use, disposal, and recycling stages by using matrix-based method. The new method is applied to the analysis of the embodied CO2 emissions of a refrigerator as a case study. The entire life cycle C02 emissions are estimated to be 2.9 tons, including indirect emissions, and the reduction in CO2 emissions due to recycling steel scrap is calculated as 48.5 kg. The authors conclude that the new method enables a consistent inventory analysis for all life cycle stages by combining process and input-output methods.

关键词： Input-output analysis matrix-based method hybrid lifecycle analysis recycling refrigerator CO2 emission.

Thermal Analysis and Experimental Validation of Parabolic Trough Collector for Solar Adsorption refrigerator

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Energy and Power Engineering 2017年第11期9卷 687-702页

作者： Mariella Mateo Rodolfo Echarri Inna Samsón Laboratorio de Energías Alternativas Instituto Tecnológico de Santo Domingo Santo Domingo Dominican Republic Instituto del Desarrollo Humano Universidad Nacional de General Sarmiento Buenos Aires Argentina Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Buenos Aires Argentina

This work presents an algorithm able to simulate the heating of a solar collector throughout the day. The discussed collector is part of a solar adsorption refrigerator, and is used to regenerate the activated carbon contained inside a cylindrical recipient (absorber), which is located in the focal line of a parabolic trough concentrator. The developed algorithm takes into account all the transfer mechanisms when analyzing the heat transfers taking place between the collector’s components and the environment, as well as the transfer mechanisms towards the absorber’s interior. The temperature evolution for the collector’s elements is obtained, and the model is validated by comparing the experimentally measured surface temperature of the absorber with the one determined by the algorithm. The experimental data were gathered from similar collectors in two different scenarios: Santo Domingo (Dominican Republic) and Buenos Aires (Argentina). The model is satisfactorily validated with experimental data.

关键词： Mathematical Model Heat Transfer Parabolic Trough Collector Solar Adsorption refrigerator