Impact of flow resistance on the operational stability of two-phase thermosyphon loop with different working fluids

IF 5.1 3区工程技术 Q2 ENERGY & FUELS

Thermal Science and Engineering Progress Pub Date : 2025-03-01 DOI:10.1016/j.tsep.2025.103463

Zhen Tong, Zhaolong Zhu, Wencheng Wang, Zekun Han

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Abstract

When a two-phase thermosyphon loop (TPTL) operates in an oscillatory state, its service life may be shortened due to mechanical impacts. Limited research exists on improving TPTL stability. This study used a needle valve to adjust the flow resistance in the downcomer of a TPTL to analyze its impact on the operational stability of CO₂ and R134a TPTLs. Our research revealed that the operating states of the two TPTLs are affected differently by flow resistance. The fluctuating operation of the CO₂ TPTL is caused by the periodic changes in the flow regime within the loop. An increase in flow resistance led to higher circulating driving force by increasing vapor quality in the riser and decreasing vapor quality in the downcomer. This suppressed the operational instability of the CO₂ TPTL. However, the unstable operation of R134a TPTL resulted from the inherent instability of the stirred flow in the riser. Therefore, the change in flow resistance has almost no effect on the operational stability of the R134a TPTL. The findings of this study provide new insights for improving the operational stability of the CO₂ TPTL.

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来源期刊

Thermal Science and Engineering Progress Chemical Engineering-Fluid Flow and Transfer Processes

CiteScore

7.20

自引率

10.40%

发文量

327

审稿时长

41 days

期刊介绍： Thermal Science and Engineering Progress (TSEP) publishes original, high-quality research articles that span activities ranging from fundamental scientific research and discussion of the more controversial thermodynamic theories, to developments in thermal engineering that are in many instances examples of the way scientists and engineers are addressing the challenges facing a growing population – smart cities and global warming – maximising thermodynamic efficiencies and minimising all heat losses. It is intended that these will be of current relevance and interest to industry, academia and other practitioners. It is evident that many specialised journals in thermal and, to some extent, in fluid disciplines tend to focus on topics that can be classified as fundamental in nature, or are ‘applied’ and near-market. Thermal Science and Engineering Progress will bridge the gap between these two areas, allowing authors to make an easy choice, should they or a journal editor feel that their papers are ‘out of scope’ when considering other journals. The range of topics covered by Thermal Science and Engineering Progress addresses the rapid rate of development being made in thermal transfer processes as they affect traditional fields, and important growth in the topical research areas of aerospace, thermal biological and medical systems, electronics and nano-technologies, renewable energy systems, food production (including agriculture), and the need to minimise man-made thermal impacts on climate change. Review articles on appropriate topics for TSEP are encouraged, although until TSEP is fully established, these will be limited in number. Before submitting such articles, please contact one of the Editors, or a member of the Editorial Advisory Board with an outline of your proposal and your expertise in the area of your review.