Two-phase flow patterns in adiabatic refrigerant flow through capillary tubes

Luka Lorbek (Author), Anja Kuhelj (Author), Matevž Dular (Author), Andrej Kitanovski (Author)

Abstract

This paper presents the results of an experimental study of the flow visualization of the refrigerant R600a through a capillary tube with an internal diameter of 0.8 mm made from an FEP (fluorinated ethylene propylene) polymer that was installed in a small-scale vapor-compression refrigeration system. The main purpose of the study was to determine the flow patterns of the refrigerant flow in capillary tubes under different operating conditions and to verify whether the results obtained using an FEP tube are representative for the flow of a refrigerant in copper capillary tubes. The results of the study revealed that the two-phase refrigerant flow in the FEP capillary tubes consists predominantly of a heterogenous flow composed of slugs, which continuously expand downstream. It was also found that at higher inlet pressures the frequency at which the vapor inception occurs is higher than at lower pressures. In addition, an experimental study of the effect of local or global imperfections on the inner surface of the FEP tube was performed. In some cases, the imperfections increased the number of vapor bubble inception points, which caused a homogenization of the two-phase flow.

Keywords

refrigeration;vapor-compression system;refrigerant flow;capillary tube;evaporation;flow visualization;

Data

Language:	English
Year of publishing:	2020
Typology:	1.01 - Original Scientific Article
Organization:	UL FS - Faculty of Mechanical Engineering
UDC:	621.56(045)
COBISS:	17060891
ISSN:	0140-7007
Views:	419
Downloads:	198
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	French
Secondary title:	Configurations d'écoulement diphasique pour un écoulement de frigorigène adiabatique à travers des tubes capillaires
Secondary keywords:	hlajenje;parno kompresijski sistem;tok hladiva;kapilara;uparjanje;vizualizacija toka;
Pages:	str. 107-116
Issue:	ǂVol. ǂ115
Chronology:	2020
DOI:	10.1016/j.ijrefrig.2020.02.030
ID:	12355858