PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 12

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Validation of the generalized model of two-phase thermosyphon loop based on experimental measurements of volumetric flow rate
Bieliński H.
Archives of Thermodynamics
|
2016
|
Vol. 37, no. 3
109--138
EN
The current paper presents the experimental validation of the generalized model of the two-phase thermosyphon loop. The generalized model is based on mass, momentum, and energy balances in the evaporators, rising tube, condensers and the falling tube. The theoretical analysis and the experimental data have been obtained for a new designed variant. The variant refers to a thermosyphon loop with both minichannels and conventional tubes. The thermosyphon loop consists of an evaporator on the lower vertical section and a condenser on the upper vertical section. The one-dimensional homogeneous and separated two-phase flow models were used in calculations. The latest minichannel heat transfer correlations available in literature were applied. A numerical analysis of the volumetric flow rate in the steady-state has been done. The experiment was conducted on a specially designed test apparatus. Ultrapure water was used as a working fluid. The results show that the theoretical predictions are in good agreement with the measured volumetric flow rate at steady-state.
2
Content available Application of a two-phase thermosyphon loop with minichannels and a minipump in computer cooling
Bieliński H., Mikielewicz J.
Archives of Thermodynamics
|
2016
|
Vol. 37, no. 1
3--16
EN
This paper focuses on the computer cooling capacity using the thermosyphon loop with minichannels and minipump. The one-dimensional separate model of two-phase flow and heat transfer in a closed thermosyphon loop with minichannels and minipump has been used in calculations. The latest correlations for minichannels available in literature have been applied. This model is based on mass, momentum, and energy balances in the evaporator, rising tube, condenser and the falling tube. A numerical analysis of the mass flux and heat transfer coefficient in the steady state has been presented.
3
Content available remote A two phase thermosyphon loop with minichannels heated from the vertical side and cooled from the horizontal one
Bieliński H., Mikielewicz J.
Chemical and Process Engineering
|
2010
|
Vol. 31, z. 4
535-551
EN
A one-dimensional model of two-phase flow and heat transfer has been presented for a closed thermosyphon loop with minichannels heated from the vertical side and cooled from the horizontal one. The model is based on mass, momentum, and energy balances in an evaporator, rising tube, condenser and a falling tube. A separated two-phase flow model is used in calculations. The effect of geometrical parameters of the loop on the mass flux rate in a steady state has been numerically examined. A numerical analysis of the heat transfer coefficient in a flow boiling and condensation has been done.
PL
Przedstawiono jednowymiarowy model wymiany ciepła i przepływu płynu dwufazowego w minikanałowym, zamkniętym obiegu termosyfonowym z ogrzewaniem pionowego odcinka obiegu i chłodzeniem na odcinku poziomym. W modelu sformułowano równania zachowania masy, ruchu i energii dla grzejnika, chłodnicy i kanałów łączących. Analizę oparto na modelu rozdzielonym przepływu czynnika dwufazowego. Określono numerycznie wpływ parametrów geometrycznych obiegu na wartość masowej prędkości zredukowanej w stanie ustalonym. Przedstawiono rozkład współczynnika przejmowania ciepła podczas wrzenia i kondensacji w przepływie czynnika dwufazowego.
4
Content available Computer cooling using a two phase minichannel thermosyphon loop heated from horizontal and vertical sides and cooled from vertical side
Bieliński H., Mikielewicz J.
Archives of Thermodynamics
|
2010
|
Vol. 31, no. 4
51-59
EN
In the present paper it is proposed to consider the computer cooling capacity using the thermosyphon loop. A closed thermosyphon loop consists of combined two heaters and a cooler connected to each other by tubes. The first heater may be a CPU processor located on the motherboard of the personal computer. The second heater may be a chip of a graphic card placed perpendicular to the motherboard of personal computer. The cooler can be placed above the heaters on the computer chassis. The thermosyphon cooling system on the use of computer can be modeled using the rectangular thermosyphon loop with minichannels heated at the bottom horizontal side and the bottom vertical side and cooled at the upper vertical side. The riser and a downcomer connect these parts. A one-dimensional model of two-phase flow and heat transfer in a closed thermosyphon loop is based on mass, momentum, and energy balances in the evaporators, rising tube, condenser and the falling tube. The separate two-phase flow model is used in calculations. A numerical investigation for the analysis of the mass flux rate and heat transfer coefficient in the steady state has been accomplished.
5
Content available remote The effect of geometrical parameters on the mass flux in a two phase thermosyphon loop heated from one side
Bieliński H., Mikielewicz J.
Archives of Thermodynamics
|
2008
|
Vol. 29, no. 1
59-68
EN
In the paper the authors present a one-dimensional model of two-phase flow and heat transfer in a closed thermosyphon loop. The presented model is based on mass, momentum, and energy balances in the evaporator, rising tube, condenser, and the falling tube. The homogeneous and separate two-phase flow models are used in calculations. The effect of geometrical parameters of the loop on the mass flux rate in the steady state is examined numerically.
6
Content available remote Mass flux and heat transfer coefficient in two phase thermosyphon loop heated from a horizontal side and cooled from the vertical side
Bieliński H., Mikielewicz J.
Archives of Thermodynamics
|
2008
|
Vol. 29, no. 4
13-26
EN
The purpose of this paper is to present a one-dimensional model of two-phase flow and heat transfer in a closed thermosyphon loop heated from a horizontal side and cooled from the vertical side. The created model is based on mass, momentum, and energy balances in the evaporator, rising tube, condenser and the falling tube. The separate two-phase flow model is used in calculations. A numerical investigation for the analysis of the mass flux rate and heat transfer coefficient in the steady state has been done. Conventional tubes and minichannels are considered.
7
Content available remote The mass flux in a two-phase thermosyphon loop heated from one side
Bieliński H., Mikielewicz J.
Archives of Thermodynamics
|
2006
|
Vol. 27, no. 4
35-44
EN
In the paper the authors present a one-dimensional model of two-phase flow and heat transfer in a closed thermosyphon loop. The presented model is based on mass, momentum, and energy balances in the evaporator, rising tube, condenser, and the falling tube. The homogeneous and separate two-phase flow models are used in calculations. The mass flux in the steady state is examined numerically using Muller-Steinhagen formula for two phase flow calculations.
8
Dwufazowy obieg termosyfonowy z ogrzewaniem bocznym
Bieliński H., Mikielewicz J.
Inżynieria Chemiczna i Procesowa
|
2005
|
T. 26, z. 2
339-351
PL
Przedstawiono model termosyfonu dwufazowego z ogrzewaniem bocznym. Zamknięte termosyfony umożliwiają transport ciepła za pomocą konwekcji naturalnej. Analizę ruchu płynu i wymiany ciepła oparto na stacjonarnym, jednowymiarowym modelu. Dwufazowy przepływu płynu opisano za pomocą modelu poślizgowego. Pokazano wpływ geometrii na wartość masowego natężenia przepływu płynu dwufazowego w stanie ustalonym.
EN
Two-phase thermosyphon with lateral heating is presented in this paper. Closed thermosyphon loops are devices capable of transporting heat through natural convection process. The analysis of fluid flow and heat transfer is based on the one-dimensional model at a steady-state. The slip two-phase flow model is used in calculations. It is shown that geometrical parameter of loop have influence on the mass flow rate at the steady-state.
9
Content available remote Natural circulation in two-phase thermosyphon loop heated from below
Bieliński H., Mikielewicz J.
Archives of Thermodynamics
|
2004
|
Vol. 25, no. 3
15-26
EN
Closed thermosyphon loops are devices capable of transporting heat through natural convection process. This paper focuses on the steady-state behaviour of two-phase natural circulation loops i.e. thermosyphon loops, in which the density difference of fluid between its liquid and vapour phases is a driving force. The steady-state, one-dimensional model is proposed for two-phase thermosyphon. The presented model based on mass, momentum, and energy balances in the evaporator, rising tube, condenser, and the falling tube. The slip two-phase flow model is used in circulations. The effect of the loop.s aspect ratio (height H to the breadth B) on the mass flow rate at the steady-state is examined numerically. Results show that the mass flow rate increases with increasing aspect ratio H/B. Freon R-11 was chosen as a working fluid in the thermosyphon device.
10
Content available remote New solutions of thermal diode with natural turbulent circulation
Bieliński H., Mikielewicz J.
Archives of Thermodynamics
|
2002
|
Vol. 23, no 1-2
23-38
EN
The thermal diode allows heat to be transferred in one direction, preventing the transfer of heat in the opposite direction. Two new models of the thermal diode are presented in this paper. The first model describes the thermal diode heated simultaneously from below and symmetrically from the sides, while the second model demonstrates the thermal diode heated from a lower part of one side and cooled from the upper part of the opposite side. The analysis of fluid flow and heat transfer is based on a one-dimensional model. Distributions of temperature and mass flow rate are obtained for the steady-state turbulent flow. It is shown that the geometrical and thermal parameters have an influence on the steady-state flow rate.
11
Content available remote New solutions of thermal diode with natural laminar circulation
Bieliński H., Mikielewicz J.
Archives of Thermodynamics
|
2001
|
Vol. 22, nr 1-2
89-106
EN
The thermal diode allows the heat to be transferred in one direction, preventing the transfer of heat in the opposite direction. Two new models of the thermal diode are presented in this paper. The first model describes the thermal diode heated simultaneously from below and symmetrically from the sides, whilst the second model demonstrates the thermal diode heated from a lower part of one side and cooled from the upper part of the opposite side. The analysis of fluid flow and heat transfer is based on a one-demensional model. Distributions of temperature and mass flow rate are obtained for steady-state laminar flow. Numerical calculations are performed for the onset of motion of the fluid from rest. It is shown that the geometrical and thermal parameters have an influence on both the steady-state flow rate and the problem of global flow initiation from the rest.
12
Dioda termiczna ogrzewana od dołu i z boku. Wpływ geometrii obiegu na strumień masy w ruchu turbulentnym
Bieliński H., Mikielewicz J.
Prace Naukowe Instytutu Techniki Cieplnej i Mechaniki Płynów Politechniki Wrocławskiej. Konferencje
|
2000
|
Vol. 56, nr 10
153-160
PL
Zaprezentowano model teoretyczny diody termicznej ogrzewanej od dołu i z boku. Analizę wymiany ciepła i ruchu płynu oparto na modelu jednowymiarowym. Przedstawiono również rozkłady temperatur i profil strumienia masy czynnika w ruchu turbulentnym. Zaprezentowano wpływ geometrii obiegu na strumień masy w ruchu turbulentnym.
EN
The idea of the "thermal diode" is based on the natural circulation of the fluid around the closed-loop thermosyphon. A model of the "thermal diode" heated at the bottom and from one side are presented. Fluid flow and heat transfer analysis is based on a one-dimensional model. The temperature distributions and mass flow rates are obtained for turbulent flow at the steady-state. The effect of the loop aspect ratio on the mass flow rate for turbulent flow at the steady state have been obtained.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.