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Jincan Chen - One of the best experts on this subject based on the ideXlab platform.

  • Optimal thermoeconomic performance of an irreversible regenerative ferromagnetic Ericsson Refrigeration Cycle
    Journal of Magnetism and Magnetic Materials, 2016
    Co-Authors: Zhichao Xu, Jincan Chen
    Abstract:

    Abstract On the basis of the Langevin theory of classical statistical mechanics, the magnetization, entropy, and iso-field heat capacity of ferromagnetic materials are analyzed and their mathematical expressions are derived. An irreversible regenerative Ericsson Refrigeration Cycle by using a ferromagnetic material as the working substance is established, in which finite heat capacity rates of low and high temperature reservoirs, non-perfect regenerative heat of the Refrigeration Cycle, additional regenerative heat loss, etc. are taken into account. Based on the regenerative Refrigeration Cycle model, a thermoeconomic function is introduced as one objective function and optimized with respect to the temperatures of the working substance in the two iso-thermal processes. By means of numerical calculation, the effects of the effective factor of the heat exchangers in high/low temperature reservoir sides, efficiency of the regenerator, heat capacity rate of the low temperature reservoir, and applied magnetic field on the optimal thermoeconomic function as well as the corresponding cooling rate and coefficient of performance are revealed. The results obtained in this paper can provide some theoretical guidance for the optimal design of actual regenerative magnetic refrigerator Cycle.

  • Influence of regeneration on the performance of a Brayton Refrigeration-Cycle working with an ideal Bose-gas
    Applied Energy, 2006
    Co-Authors: Yulin Yang, Bihong Lin, Jincan Chen
    Abstract:

    A general regenerative model of the Brayton Refrigeration-Cycle working with an ideal Bose-gas is used to discuss the influence of both the quantum degeneracy and regeneration on the performance of the Cycle. Expressions for some important parameters, such as the Refrigeration load, work input, coefficient of performance and minimum pressure-ratio, of the Brayton Refrigeration-Cycle are derived analytically and used to generate the Refrigeration load, work input, coefficient of performance, and relative Refrigeration-load versus pressure ratio curves. Moreover, several special cases are discussed in detail. The results obtained here will be helpful to reveal the performance characteristics of the Bose-Brayton Refrigeration-Cycle, further understand the difference and connection between the classical and quantum Brayton Refrigeration-Cycles, and theoretically expound the importance of the regeneration application for the Brayton Refrigeration-Cycle.

  • The performance characteristics of an irreversible regenerative quantum Refrigeration Cycle
    Physica Scripta, 2005
    Co-Authors: Yue Zhang, Bihong Lin, Jincan Chen
    Abstract:

    An irreversible regenerative model of the Brayton Refrigeration Cycle working with an ideal Fermi gas, which is simply called the quantum Refrigeration Cycle, is established. Expressions for several important performance parameters, such as the coefficient of performance, work input, Refrigeration load and regeneration heat, are derived, based on the equation of state of an ideal Fermi gas. The influence of quantum degeneracy of the gas, regeneration and irreversibility on the performance of the quantum Refrigeration Cycle is analysed comprehensively. The general performance characteristics of the Cycle are revealed. Moreover, two special cases are discussed and compared in detail. Consequently, the importance of regeneration in the cryogenic Refrigeration is expounded from theory. Finally, the performance of the Brayton Refrigeration Cycle at high temperatures is directly deduced.

  • The influence of quantum degeneracy and irreversibility on the performance of a Fermi quantum Refrigeration Cycle
    Journal of Physics A: Mathematical and General, 2004
    Co-Authors: Yue Zhang, Bihong Lin, Jincan Chen
    Abstract:

    An irreversible Cycle model of the quantum Refrigeration Cycle using an ideal Fermi gas as the working substance is established. The Cycle consists of two adiabatic and two isobaric processes and consequently may be simply referred to as the Fermi Brayton Refrigeration Cycle. The performance of the Cycle is investigated, based on the equation of state of an ideal Fermi gas. Expressions for several important performance parameters, such as the coefficient of performance, work input and Refrigeration load, are derived. The influence of the quantum degeneracy of the Fermi gas and the irreversibility in the Cycle on the performance of the Fermi Brayton Refrigeration Cycle is analysed. The minimum pressure ratio of the Cycle is determined. The optimally operating problems of the Cycle and several special cases are discussed in detail. The results obtained here are general and may reveal the general performance characteristics of the Fermi Brayton Refrigeration Cycle.

  • Optimal analysis on the performance of an irreversible harmonic quantum Brayton Refrigeration Cycle.
    Physical Review E, 2003
    Co-Authors: Jincan Chen
    Abstract:

    : An irreversible model of a quantum Refrigeration Cycle working with many noninteracting harmonic oscillators is established. The Refrigeration Cycle consists of two adiabatic and two constant-frequency processes. The general performance characteristics of the Cycle are investigated, based on the quantum master equation and the semigroup approach. The expressions for several important performance parameters such as the coefficient of performance, cooling rate, power input, and rate of entropy production are derived. By using numerical solutions, the cooling rate of the Refrigeration Cycle subject to finite Cycle duration is optimized. The maximum cooling rate and the corresponding parameters are calculated numerically. The optimal region of the coefficient of performance and the optimal ranges of temperatures of the working substance and times spent on the two constant-frequency processes are determined. Moreover, the optimal performance of the Cycle in the high-temperature limit is compared with that of a classical Brayton refrigerator working with an ideal gas. The results obtained here show that in the high-temperature limit a harmonic quantum Brayton Cycle may be equivalent to a classical Brayton Cycle.

Jianlin Yu - One of the best experts on this subject based on the ideXlab platform.

  • theoretical investigation on the performance of an ejector enhanced Refrigeration Cycle using hydrocarbon mixture r290 r600a
    Applied Thermal Engineering, 2020
    Co-Authors: Qi Chen, Yunho Hwang, Jianlin Yu
    Abstract:

    Abstract This paper proposes an ejector enhanced vapor compression Refrigeration Cycle (EVRC) using zeotropic hydrocarbon mixture R290/R600a for applications in domestic refrigerator/freezers. An internal heat exchanger and a phase separator are utilized in EVRC to improve the system performance. An ejector is adopted to further enhance the Cycle performance. The energy and exergy analysis of EVRC are performed to evaluate the system operating characteristics and compared with the Lorenz-Meutzer vapor compression Refrigeration Cycle (LVRC) and the traditional vapor compression Refrigeration Cycle (TVRC). The results indicate that EVRC can provide the uppermost advantages over both TVRC and LVRC under the operating conditions. Compared with TVRC, the EVRC can significantly improve the coefficient of performance, volumetric Refrigeration capacity and exergy efficiency by 13.5%, 19.3%, and 13.4%, respectively. The performance characteristics of the proposed Cycle demonstrate its potential advantages for application in domestic refrigerator/freezers.

  • performance evaluation of an ejector subcooled vapor compression Refrigeration Cycle
    Energy Conversion and Management, 2015
    Co-Authors: Meibo Xing, Jianlin Yu
    Abstract:

    Abstract In this study, a novel vapor-compression Refrigeration Cycle with mechanical subcooling using an ejector is proposed to improve the performance of a conventional single-stage vapor-compression Refrigeration Cycle. In the theoretical study, a mathematical model is developed to predict the performance of the Cycle by using R404A and R290, and then compared with that of the conventional Refrigeration Cycle. The simulation results show that the performance of the ejector subcooled Cycle is better than that of the conventional Cycle. When the evaporator temperature ranges from −40 to −10 °C and the condenser temperature is 45 °C, the novel Cycle displays volumetric Refrigeration capacity improvements of 11.7% with R404A and 7.2% with R290. And the novel Cycle achieves COP improvements of 9.5% with R404A and 7.0% with R290. In addition, the improvement of the COP and cooling capacity of this novel Cycle largely depends on the operation pressures of the ejector. The potential practical advantages offered by the Cycle may be worth further attention in future studies.

  • Theoretical study on a novel dual-nozzle ejector enhanced Refrigeration Cycle for household refrigerator-freezers
    Energy Conversion and Management, 2013
    Co-Authors: Mengliu Zhou, Xiao Wang, Jianlin Yu
    Abstract:

    Abstract In this study, a novel dual-nozzle ejector enhanced Refrigeration Cycle is presented for dual evaporator household refrigerator-freezers. The proposed ejector equipped with two nozzles can efficiently recover the expansion work from Cycle throttling processes and enhance Cycle performances. The performances of the novel Cycle are evaluated by using the developed mathematical model, and then compared with that of the conventional ejector enhanced Refrigeration Cycle and basic vapor-compression Refrigeration Cycle. The simulation results show that for the given operating conditions, the coefficient of performance (COP) of the novel Cycle using refrigerant R134a is improved by 22.9–50.8% compared with that of the basic vapor-compression Refrigeration Cycle, and the COP improvement is 10.5–30.8% larger than that of the conventional ejector enhanced Refrigeration Cycle. The further simulation results of the novel Cycle using refrigerant R600a indicate that the Cycle COP and volumetric Refrigeration capacity could be significantly improved.

Thanarath Sriveerakul - One of the best experts on this subject based on the ideXlab platform.

  • analysis of a combined rankine vapour compression Refrigeration Cycle
    Energy Conversion and Management, 2010
    Co-Authors: Satha Aphornratana, Thanarath Sriveerakul
    Abstract:

    Abstract This paper describes a theoretical analysis of a heat-powered Refrigeration Cycle, a combined Rankine–vapour–compression Refrigeration Cycle. This Refrigeration Cycle combines an Organic Rankine Cycle and a vapour–compression Cycle. The Cycle can be powered by low grade thermal energy as low as 60 °C and can produce cooling temperature as low as −10 °C. In the analysis, two combined Rankine–vapour–compression Refrigeration Cycles were investigated: the system with R22 and the system with R134a. Calculated COP values between 0.1 and 0.6 of both the systems were found.

  • Analysis of a combined Rankine–vapour–compression Refrigeration Cycle
    Energy Conversion and Management, 2010
    Co-Authors: Satha Aphornratana, Thanarath Sriveerakul
    Abstract:

    Abstract This paper describes a theoretical analysis of a heat-powered Refrigeration Cycle, a combined Rankine–vapour–compression Refrigeration Cycle. This Refrigeration Cycle combines an Organic Rankine Cycle and a vapour–compression Cycle. The Cycle can be powered by low grade thermal energy as low as 60 °C and can produce cooling temperature as low as −10 °C. In the analysis, two combined Rankine–vapour–compression Refrigeration Cycles were investigated: the system with R22 and the system with R134a. Calculated COP values between 0.1 and 0.6 of both the systems were found.

  • Development of a circulating system for a jet Refrigeration Cycle
    International Journal of Refrigeration, 2008
    Co-Authors: Passakorn Srisastra, Satha Aphornratana, Thanarath Sriveerakul
    Abstract:

    This paper proposed a workless-generator-feeding (WGF) system for a jet Refrigeration Cycle, using R141b. This feeding system does not require any mechanical power. The liquid refrigerant from the condenser was fed to the vapour-generator by means of the generator pressure and gravitational force. The system was tested and compared with a conventional system using a mechanical pump. It was found that this system was workable. The heat input to the generator was slightly higher than that for a system using a mechanical pump. The jet Refrigeration Cycle employing this new feeding system provided a slightly lower coefficient of performance (COP) compared to a system using a mechanical pump. However, this new system did not require any mechanical energy. Therefore, the jet Refrigeration system employing this WGF system is truly a heat-power Refrigeration Cycle.

Sun Fangtian - One of the best experts on this subject based on the ideXlab platform.

  • thermodynamic analysis of transcritical co2 Refrigeration Cycle with an ejector
    Applied Thermal Engineering, 2011
    Co-Authors: Sun Fangtian, Ma Yitai
    Abstract:

    A comparative study on transcritical carbon dioxide Refrigeration Cycle with ejector and with throttling valve was performed by the first and second laws of thermodynamics in theory. The effects of the entrainment ratio of the ejector, heat rejection pressure, outlet temperature of gas cooler and evaporating temperature on the coefficient of performance (COP) and exergy loss were investigated in transcritical carbon dioxide Refrigeration Cycle with ejector and with throttling valve. It is found that ejector instead of throttling valve can reduce more 25% exergy loss and increase COP more 30%. In addition, critical entrainment ratio of the ejector, optimal heat rejection pressure and critical outlet temperature of gas cooler affects COP greatly for the transcritical carbon dioxide refrigerating Cycle with ejector.

Ma Yitai - One of the best experts on this subject based on the ideXlab platform.

  • thermodynamic analysis of transcritical co2 Refrigeration Cycle with an ejector
    Applied Thermal Engineering, 2011
    Co-Authors: Sun Fangtian, Ma Yitai
    Abstract:

    A comparative study on transcritical carbon dioxide Refrigeration Cycle with ejector and with throttling valve was performed by the first and second laws of thermodynamics in theory. The effects of the entrainment ratio of the ejector, heat rejection pressure, outlet temperature of gas cooler and evaporating temperature on the coefficient of performance (COP) and exergy loss were investigated in transcritical carbon dioxide Refrigeration Cycle with ejector and with throttling valve. It is found that ejector instead of throttling valve can reduce more 25% exergy loss and increase COP more 30%. In addition, critical entrainment ratio of the ejector, optimal heat rejection pressure and critical outlet temperature of gas cooler affects COP greatly for the transcritical carbon dioxide refrigerating Cycle with ejector.

  • Exergy Analysis of Transcritical Carbon Dioxide Refrigeration Cycle with an Ejector
    2011 International Conference on Computer Distributed Control and Intelligent Environmental Monitoring, 2011
    Co-Authors: Sun Fang-tian, Ma Yitai, Wei Yun-xia, Li Deying
    Abstract:

    The throttling loss is the major loss of the transcritical carbon dioxide Refrigeration Cycle, and the reason of low efficiency for performance. The study on the transcritical carbon dioxide Refrigeration Cycle with ejector and with throttling valve has been performed by the first and second laws of thermodynamics in theory. The effects of the injection ratio of ejector, heat rejection pressure, outlet temperature of gas cooler and evaporating temperature on the coefficient of performance (COP) and exergy loss were investigated in transcritical carbon dioxide Refrigeration Cycle with ejector and with throttling valve. It is found that ejector instead of throttling valve can reduce more 70% exergy loss and increases COP more 36%. In addition, optimal heat rejection pressure and outlet temperature of gas cooler affect COP greatly for the transcritical carbon dioxide refrigerating Cycle with ejector.