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 Santa 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.

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

Filippeschi, Sauro;Mameli, Mauro;Fantozzi, Fabio
2019-01-01

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 Santa 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.
2019
Bellani, Pedro; Milanez, Fernando; Mantelli, Marcia Barbosa Henriques; Filippeschi, Sauro; Mameli, Mauro; Fantozzi, Fabio
File in questo prodotto:
File Dimensione Formato  
IPHT0701(5)-31160.pdf

solo utenti autorizzati

Tipologia: Versione finale editoriale
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 967.9 kB
Formato Adobe PDF
967.9 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/1019877
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 1
  • ???jsp.display-item.citation.isi??? 0
social impact