THEORETICAL AND EXPERIMENTAL ANALYSES OF THE THERMAL RESISTANCE OF A LOOP THERMOSYPHON FOR PASSIVE SOLAR HEATING OF BUILDINGS

IF 0.7 Q4 THERMODYNAMICS

Interfacial Phenomena and Heat Transfer Pub Date : 2019-01-01 DOI:10.1615/INTERFACPHENOMHEATTRANSFER.2019031160

P. Bellani, F. Milanez, M. Mantelli, S. Filippeschi, M. Mameli, F. Fantozzi

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引用次数: 2

Abstract

This study presents experimental and theoretical analyses of the thermal performance of a two-phase copper-R141b loop thermosyphon, which was developed for solar heating of buildings. A prototype of the so-called wall thermosyphon was built and tested at the Heat Pipe Laboratory of the Federal University of Catarina (Labtucal-UFSC). During the tests, three parameters were varied: purge method, power input levels, and inside wall evaporator roughness. The results show that both purge and vacuum pumps are equally effective in eliminating noncondensable gases from the system. Also, recent boiling heat transfer coefﬁcient literature correlations are in good agreement with the experimental data from the prototype. However, the condensation thermal resistance calculated with the literature correlations do not represent the same trend found in the experiments. The effective thermal resistance of the wall thermosyphon prototype, which comprises the boiling resistance plus the condensation resistance, varies between 0.22 and 0.011 ◦ C/W depending on the heat transfer rate from 2.5 to 200 W.

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建筑被动式太阳能采暖循环热虹吸热阻的理论与实验分析

本文对用于建筑太阳能供暖的两相铜- r141b环形热虹吸管的热性能进行了实验和理论分析。在卡塔琳娜联邦大学(Labtucal-UFSC)的热管实验室，建造了一个所谓的壁式热虹吸的原型并进行了测试。在试验过程中，改变了三个参数:吹扫方式、功率输入水平和内壁蒸发器粗糙度。结果表明，吹扫泵和真空泵在排除系统中不凝性气体方面同样有效。沸水换热系数的相关文献也与原型机的实验数据吻合较好。然而，用文献相关性计算的冷凝热阻并不代表实验中发现的相同趋势。壁式热虹吸管原型的有效热阻，包括沸腾阻力加上冷凝阻力，根据2.5至200 W的传热速率，在0.22至0.011◦C/W之间变化。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Interfacial Phenomena and Heat Transfer THERMODYNAMICS-

CiteScore

1.70

自引率

40.00%

发文量

期刊介绍： Interfacial Phenomena and Heat Transfer aims to serve as a forum to advance understanding of fundamental and applied areas on interfacial phenomena, fluid flow, and heat transfer through interdisciplinary research. The special feature of the Journal is to highlight multi-scale phenomena involved in physical and/or chemical behaviors in the context of both classical and new unsolved problems of thermal physics, fluid mechanics, and interfacial phenomena. This goal is fulfilled by publishing novel research on experimental, theoretical and computational methods, assigning priority to comprehensive works covering at least two of the above three approaches. The scope of the Journal covers interdisciplinary areas of physics of fluids, heat and mass transfer, physical chemistry and engineering in macro-, meso-, micro-, and nano-scale. As such review papers, full-length articles and short communications are sought on the following areas: intense heat and mass transfer systems; flows in channels and complex fluid systems; physics of contact line, wetting and thermocapillary flows; instabilities and flow patterns; two-phase systems behavior including films, drops, rivulets, spray, jets, and bubbles; phase change phenomena such as boiling, evaporation, condensation and solidification; multi-scaled textured, soft or heterogeneous surfaces; and gravity dependent phenomena, e.g. processes in micro- and hyper-gravity. The Journal may also consider significant contributions related to the development of innovative experimental techniques, and instrumentation demonstrating advancement of science in the focus areas of this journal.