Influence of the flow structure on heat transfer in the condensation process of environmentally friendly refrigerants in mini-channels
author:
MAŁGORZATA SIKORA, TADEUSZ BOHDAL
ORCID ID:
0000-0001-8373-3573, 0000-0002-0621-2894
No:
05/2022 Instal p. 20-26
DOI:
DOI 10.36119/15.2022.5.4
During the condensation process in the mini-channels, the heat and mass transfer mechanisms change, resulting
from the change in the vapor quality x and the void fraction φ, which in turn affect the process of formation of
various flow structures. The measure of the energy efficiency of the process is the heat transfer coefficient α, which
depends on the kind of the two-phase flow. This article presents the influence of the two-phase flow structures formed
during the condensation process in horizontal pipe mini-channels on the heat transfer process. The research was
carried out on three pro-ecological low-pressure refrigerants with low ODP and GWP coefficients, HFE7000,
HFE7100, and Novec649. The condensation process took place in pipe mini-channels with an internal diameter of
dh = 2.0; 1.2; 0.8; 0.5 mm
Keywords:
About Authors:
dr hab. inż. prof. PK Małgorzata Sikora https://orcid.org/ 0000-0001-8373-3573, prof. dr hab. inż. Tadeusz Bohdal https://orcid.org/
0000-0002-0621-2894 – Politechnika Koszalińska, Katedra Energetyki, Koszalin, Poland, Corresponding
author: malgorzata.sikora@tu.koszalin.p