Wyniki wyszukiwania - BazTech

1

The effect of capillary pumping on the course of cleaning porous materials containing liquid contaminants using supercritical fluids – A pore network study

Krzysztoforski Jan, Khayrat Karim, Henczka Marek, Jenny Patrick

Chemical and Process Engineering

|

2021

|

Vol. 42, nr 4

349-–368

EN

The role of capillary pumping on the course of cleaning porous materials containing liquid contaminants using supercritical fluids was investigated numerically. As a specific process to be modelled, cleaning of porous membranes, contaminated with soybean oil, using supercritical carbon dioxide as the cleaning fluid (solvent) was considered. A 3D pore-network model, developed as an extension of a 2D drying model, was used for performing pore scale simulations. The influence of various process parameters, including the coordination number of the pore network, the computational domain size, and the external flow mass transfer resistance, on the strength of the capillary pumping effect was investigated. The capillary pumping effect increases with increasing domain size and decreasing external flow mass transfer resistance. For low coordination numbers of the pore network, the capillary pumping effect is not noticeable at macro scale, while for high coordination numbers, the opposite trend is observed – capillary pumping may influence the process at macro scale. In the investigated system, the coordination number of the pore network seems to be low, as no capillary pumping effects were observed at macro scale during experimental investigation and macro-scale modelling of the membrane cleaning process.

2

Numerical analysis of evaporation in microchannel under capillary pumping

Karwacki J., Nowakowska H., Lackowski M., Butrymowicz D.

Archives of Thermodynamics

|

2015

|

Vol. 36, no. 2

3--25

EN

The paper presents numerical simulation of two-phase flow in a heated capillary with evaporation on the meniscus. To solve the problem, a model of evaporation from meniscus was developed in which the dynamics of liquid-vapour interface is described by the Cahn-Hilliard equation. The numerical simulations were performed using commercial software for 2D axially symmetric case. The flow evolution was analysed for different values of heat transfer coefficient at the capillary wall and inlet liquid mass flow rate.

3

Zagadnienia wykorzystania pompowania kapilarnego w mikrokanałowych wymiennikach ciepła

Karwacki J., Butrymowicz D., Mikielewicz J.

Technika Chłodnicza i Klimatyzacyjna

|

2014

|

nr 2

48--53

PL

W artykule przedstawiono wybrane wyniki prac badawczych prowadzonych w Instytucie Maszyn Przepływowych PAN w Gdańsku w zakresie poprawy efektywności energetycznej mikrokanałowych wymienników ciepła stosowanych między innymi w obiegach pracujących z czynnikami naturalnymi. Jednym z podstawowych oczekiwań jest znacząca redukcja napełnienia tych wymienników z uwagi na palność bądź wybuchowość czynnika roboczego. Omówiono zagadnienie efektów kapilarnych występujących w mini i mikrokanałowych wymiennikach ciepła wraz z prezentacją modelu występującego w nich pompowania kapilarnego.

EN

The paper presents selected results of research conducted at the Institute of Fluid-Flow Machinery Polish Academy of Sciences in Gdansk in improving the energy efficiency of microchannel heat exchangers used, inter alia, in the circuits working with natural factors. One of the basic expectations is a significant reduction of the content of these heat exchangers due to the flammability or explosive medium. Discussed the issue of capillary effects occurring in the mini and microchannel heat exchangers with a presentation model that appears in the capillary pumping them.

4

Analiza zastosowania pompowania kapilarnego w mikrokanałowych parownikach

Karwacki J., Butrymowicz D.

Chłodnictwo : organ Naczelnej Organizacji Technicznej

|

2014

|

R. 49, nr 11-12

6--10

PL

W artykule rozpatrzono zagadnienie pompowania kapilarnego czynnika roboczego w aspekcie zastosowania tego rozwiązania w układach wymienników mini kanałowych bądź mikrokanałowych. Zaproponowano model pompowania kapilarnego w minikanałach w warunkach wrzenia, wskazując na zasadnicze kryteria geometryczne oraz cieplne niezbędne do uzyskania tego zjawiska.

EN

The paper deal with analysis of the effect of capillary pumping in microchannels. This capillary pumping is the combined with the liquid meniscus in micro heat exchangers. This meniscus creates the pressure differences between liquid phase and vapour phase. The pressure of the liquid phase is lower than the pressure of the vapour phase. This phenomenon can reduce the resistance of the flow. From application point of view this effect have the crucial meaning. Exemplary results of the theoretical analysis of the effect of capillary pumping will be presented and discussed in the paper.