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

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)
CountryJapan
Period07/12/202009/12/2020
Internet address
SeriesScience et Technique du Froid
ISSN0151-1637

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