Numerical analysis of flow maldistribution in large-scale liquid overfed finned-tube ammonia evaporators

M. R. Kærn, W. B. Markussen, J. Kristófersson

    Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

    69 Downloads (Orbit)

    Abstract

    The objective of the research is to analyze the effect of flow maldistribution in different evaporators for industrial refrigeration systems with ammonia. As the minimization of refrigerant charge has become increasingly important in these systems, refrigeration engineers and equipment manufacturers are developing new ways to control the evaporator overfeeding or circulation ratio close to unity. These efforts bring along challenges regarding flow maldistribution and possibly large superheated or unused heat exchanger areas in the evaporators. In the current research, we simulated the refrigerant flow distribution numerically, in order to understand the consequences in terms of cooling capacity for different tube circuitries as the recirculation ratio was reduced towards unity. The different tube circuitries involved two bottom-fed evaporators, (a traditional straight through and a crossover or interlaced circuitry) and one side-fed evaporator with and without inlet orifices to outbalance the liquid column in the inlet header. The results showed that the bottom fed evaporator with crossover circuitry revealed the best performance at low recirculation ratio and was robust towards airflow maldistribution. The side fed evaporator showed difficulties to handle low recirculation ratios and was sensitive towards airflow maldistribution.
    Original languageEnglish
    Title of host publicationProceedings of the14th IIR-Gustav Lorentzen Conference on Natural Refrigerants
    PublisherInternational Institute of Refrigeration
    Publication date2020
    Pages251-256
    Article number1152
    ISBN (Electronic)978-2-36215-040-1
    DOIs
    Publication statusPublished - 2020
    Event14th IIR-Gustav Lorentzen Conference on Natural Refrigerants (GL2020) - , Japan
    Duration: 7 Dec 20209 Dec 2020
    https://biz.knt.co.jp/tour/2020/12/gl2020/

    Conference

    Conference14th IIR-Gustav Lorentzen Conference on Natural Refrigerants (GL2020)
    Country/TerritoryJapan
    Period07/12/202009/12/2020
    Internet address
    SeriesScience et Technique du Froid
    ISSN0151-1637

    Bibliographical note

    Copyright © IIF/IIR. Published with the authorization of the International Institute of Refrigeration (IIR): www.iifiir.org.

    Fingerprint

    Dive into the research topics of 'Numerical analysis of flow maldistribution in large-scale liquid overfed finned-tube ammonia evaporators'. Together they form a unique fingerprint.

    Cite this