Cascade refrigeration system with inverse Brayton cycle on the cold side

Niccolo Giannetti, Adriano Milazzo, Andrea Rocchetti, Kiyoshi Saito

    Research output: Contribution to journalArticle

    9 Citations (Scopus)

    Abstract

    Low temperature refrigeration of cold stores poses some specific issues: single stage, vapour compression cycles have modest COP at low evaporation temperature; cold evaporator surfaces require de-frosting and a fan for air circulation; a part of the refrigeration load may be delivered at intermediate temperature levels, e.g. for the cold store loading dock. Cascade system may improve the COP and add flexibility on the temperature levels and working fluids, but the problems related to the cold evaporator surface remain unsolved. The refrigeration system presented herein features a cascade configuration combining a vapour compression cycle and an inverse Brayton cycle. Both cycles use “natural” fluids, complying with strictest regulations. The top cycle uses Ammonia in order to increase efficiency, while the bottom cycle uses air, which directly circulates in the cold space and hence eliminates the cold heat exchanger. A detailed thermodynamic analysis allows a complete screening of the relevant design parameters for an overall system optimization. The results show that, notwithstanding the intrinsic gap of efficiency suffered by the Brayton cycle, the proposed system features an acceptable global performance and widens the implementation field of this technology. This system configuration shows a COP 50% higher than the corresponding simple Brayton cycle at temperatures of the refrigerated storage of −50 °C.

    Original languageEnglish
    Pages (from-to)986-995
    Number of pages10
    JournalApplied Thermal Engineering
    Volume127
    DOIs
    Publication statusPublished - 2017 Dec 25

    Fingerprint

    Brayton cycle
    Refrigeration
    Evaporators
    Temperature
    Vapors
    Docks
    Fluids
    Cascades (fluid mechanics)
    Air
    Fans
    Heat exchangers
    Ammonia
    Screening
    Evaporation
    Thermodynamics

    Keywords

    • Cascade system
    • Cold-store refrigeration
    • Inverse Brayton cycle
    • Performance analysis

    ASJC Scopus subject areas

    • Energy Engineering and Power Technology
    • Industrial and Manufacturing Engineering

    Cite this

    Cascade refrigeration system with inverse Brayton cycle on the cold side. / Giannetti, Niccolo; Milazzo, Adriano; Rocchetti, Andrea; Saito, Kiyoshi.

    In: Applied Thermal Engineering, Vol. 127, 25.12.2017, p. 986-995.

    Research output: Contribution to journalArticle

    @article{db7c1ae484374f3ca531c56c7d29f2a6,
    title = "Cascade refrigeration system with inverse Brayton cycle on the cold side",
    abstract = "Low temperature refrigeration of cold stores poses some specific issues: single stage, vapour compression cycles have modest COP at low evaporation temperature; cold evaporator surfaces require de-frosting and a fan for air circulation; a part of the refrigeration load may be delivered at intermediate temperature levels, e.g. for the cold store loading dock. Cascade system may improve the COP and add flexibility on the temperature levels and working fluids, but the problems related to the cold evaporator surface remain unsolved. The refrigeration system presented herein features a cascade configuration combining a vapour compression cycle and an inverse Brayton cycle. Both cycles use “natural” fluids, complying with strictest regulations. The top cycle uses Ammonia in order to increase efficiency, while the bottom cycle uses air, which directly circulates in the cold space and hence eliminates the cold heat exchanger. A detailed thermodynamic analysis allows a complete screening of the relevant design parameters for an overall system optimization. The results show that, notwithstanding the intrinsic gap of efficiency suffered by the Brayton cycle, the proposed system features an acceptable global performance and widens the implementation field of this technology. This system configuration shows a COP 50{\%} higher than the corresponding simple Brayton cycle at temperatures of the refrigerated storage of −50 °C.",
    keywords = "Cascade system, Cold-store refrigeration, Inverse Brayton cycle, Performance analysis",
    author = "Niccolo Giannetti and Adriano Milazzo and Andrea Rocchetti and Kiyoshi Saito",
    year = "2017",
    month = "12",
    day = "25",
    doi = "10.1016/j.applthermaleng.2017.08.067",
    language = "English",
    volume = "127",
    pages = "986--995",
    journal = "Applied Thermal Engineering",
    issn = "1359-4311",
    publisher = "Elsevier Limited",

    }

    TY - JOUR

    T1 - Cascade refrigeration system with inverse Brayton cycle on the cold side

    AU - Giannetti, Niccolo

    AU - Milazzo, Adriano

    AU - Rocchetti, Andrea

    AU - Saito, Kiyoshi

    PY - 2017/12/25

    Y1 - 2017/12/25

    N2 - Low temperature refrigeration of cold stores poses some specific issues: single stage, vapour compression cycles have modest COP at low evaporation temperature; cold evaporator surfaces require de-frosting and a fan for air circulation; a part of the refrigeration load may be delivered at intermediate temperature levels, e.g. for the cold store loading dock. Cascade system may improve the COP and add flexibility on the temperature levels and working fluids, but the problems related to the cold evaporator surface remain unsolved. The refrigeration system presented herein features a cascade configuration combining a vapour compression cycle and an inverse Brayton cycle. Both cycles use “natural” fluids, complying with strictest regulations. The top cycle uses Ammonia in order to increase efficiency, while the bottom cycle uses air, which directly circulates in the cold space and hence eliminates the cold heat exchanger. A detailed thermodynamic analysis allows a complete screening of the relevant design parameters for an overall system optimization. The results show that, notwithstanding the intrinsic gap of efficiency suffered by the Brayton cycle, the proposed system features an acceptable global performance and widens the implementation field of this technology. This system configuration shows a COP 50% higher than the corresponding simple Brayton cycle at temperatures of the refrigerated storage of −50 °C.

    AB - Low temperature refrigeration of cold stores poses some specific issues: single stage, vapour compression cycles have modest COP at low evaporation temperature; cold evaporator surfaces require de-frosting and a fan for air circulation; a part of the refrigeration load may be delivered at intermediate temperature levels, e.g. for the cold store loading dock. Cascade system may improve the COP and add flexibility on the temperature levels and working fluids, but the problems related to the cold evaporator surface remain unsolved. The refrigeration system presented herein features a cascade configuration combining a vapour compression cycle and an inverse Brayton cycle. Both cycles use “natural” fluids, complying with strictest regulations. The top cycle uses Ammonia in order to increase efficiency, while the bottom cycle uses air, which directly circulates in the cold space and hence eliminates the cold heat exchanger. A detailed thermodynamic analysis allows a complete screening of the relevant design parameters for an overall system optimization. The results show that, notwithstanding the intrinsic gap of efficiency suffered by the Brayton cycle, the proposed system features an acceptable global performance and widens the implementation field of this technology. This system configuration shows a COP 50% higher than the corresponding simple Brayton cycle at temperatures of the refrigerated storage of −50 °C.

    KW - Cascade system

    KW - Cold-store refrigeration

    KW - Inverse Brayton cycle

    KW - Performance analysis

    UR - http://www.scopus.com/inward/record.url?scp=85028373130&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=85028373130&partnerID=8YFLogxK

    U2 - 10.1016/j.applthermaleng.2017.08.067

    DO - 10.1016/j.applthermaleng.2017.08.067

    M3 - Article

    AN - SCOPUS:85028373130

    VL - 127

    SP - 986

    EP - 995

    JO - Applied Thermal Engineering

    JF - Applied Thermal Engineering

    SN - 1359-4311

    ER -