The effect of vapor content on the heat-exchange crisis in nonequilibrium two-phase fluxes

1972 ◽  
Vol 32 (5) ◽  
pp. 465-466
Author(s):  
L. A. Adamovich ◽  
G. M. Dvorina ◽  
V. G. Sytin
Keyword(s):  
Heat Exchange ◽  
Two Phase

Calculation of a heat-exchange crisis under dispersive-annular conditions of flow of a two-phase mixture at low pressures

1969 ◽  
Vol 26 (1) ◽  
pp. 65-65
Author(s):  
M. V. Davydova ◽  
V. N. Zelenskii ◽  
P. L. Kirillov
Keyword(s):  
Heat Exchange ◽  
Two Phase ◽  
Phase Mixture ◽  
Low Pressures

HEAT EXCHANGE PROCESSES IN POWER SEMICONDUCTOR CONVERTER INSTALLATIONS WITH EVAPORATIVE AIR COOLING

2017 ◽  
pp. 140-147
Author(s):  
Igor Kiselev ◽  
Sergey Urushev ◽  
Igor Ivanov ◽  
Yulia Vodopyanova
Keyword(s):  
Heat Exchange ◽  
Semiconductor Devices ◽  
Practical Importance ◽  
Structural Features ◽  
Air Cooling ◽  
Two Phase ◽  
Power Semiconductor ◽  
Semiconductor Converter ◽  
Exchange Processes ◽  
Improve Reliability

Objective: To improve reliability and endurance of semiconductor devices by means of heat exchange processes optimization of installations with evaporative air cooling. Methods: Design features analysis of cooling installations was applied. Results: The structural features of “a twophase thermal siphon” for power semiconductor devices were described. Experimental research of power blocks of semiconductor converter installations with “two-phase thermal siphon” coolers was conducted. The values of maximum permissible currents upon the application of possible button-type instrument configurations with such coolers were obtained. Practical importance: Application of “two-phase thermal siphon” evaporative air coolers will make it possible to improve weight-size parameters of converter installations.

Influence of selected parameters on phenomena of two-phase flow and heat exchange in TSL furnace – numerical investigation

2017 ◽  
Vol 27 (12) ◽  
pp. 2799-2815
Author(s):  
Ewa Kolczyk ◽  
Zdzisław Miczkowski ◽  
Józef Czernecki
Keyword(s):  
Numerical Simulation ◽  
Heat Exchange ◽  
Liquid Slag ◽  
Gas Flow ◽  
Two Phase Flow ◽  
New Technology ◽  
Phase Flow ◽  
Two Phase ◽  
Content Type ◽  
Submerged Lance

Purpose The purpose of this study is application of a numerical simulation for determination of the influence of geometric parameters of a furnace and hydrodynamics of the gas introduced by a vertical submerged lance on the process of feed mixing and temperature distribution. Design/methodology/approach A numerical simulation with Phoenics software was applied for modeling of liquid phase movement and heat exchange between the gas supplied through a lance and the slag feed in a top submerged lance (TSL) furnace. The simulation of a two-phase flow of a slag–gas mixture based on the inter phase slip algorithm module was conducted. The influence of selected parameters, such as depth of lance submergence, gas flow rate and change of furnace geometry, on the phenomena of movement was studied. Findings Growth of dynamics of mixing with the depth of lance submergence and with increase of gas velocity in the lance was observed. Formation of a recirculation zone in the liquid slag was registered. Movement of the slag caused by the gas flow brought homogenization of the temperature field. Originality/value The study applied the simulation of a two-phase flow in the liquid slag–gas system in steady state, taking into account heat transfer between phases. It provides possibilities for optimization and selection of process parameters within the scope of the developed new technology using a TSL furnace.

Investigation of the heat exchange of a flat element in a dynamic two-phase layer

1974 ◽  
Vol 27 (5) ◽  
pp. 1307-1309
Author(s):  
A. N. Khoze ◽  
A. P. Burdukov ◽  
B. G. Pokusaev ◽  
V. A. Kuz'min
Keyword(s):  
Heat Exchange ◽  
Two Phase ◽  
Phase Layer

Conference on Heat Exchange and Hydrostatic Resistance during the Motion of a Two-Phase Flow

1979 ◽  
Vol 46 (6) ◽  
pp. 485-486
Author(s):  
P. A. Ushakov ◽  
A. A. Ivashkevich
Keyword(s):  
Heat Exchange ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase

scholarly journals EFFECT OF OIL ON HEAT TRANSFER OF MIXED REFRIGERANT BOILING IN EVAPORATOR TUBES IN REFRIGERATION MACNINES

2019 ◽  
pp. 88-93
Author(s):  
Alexey Vasilievich Ezhov ◽  
Sergey Sergeevich Ivanov ◽  
Aleksandr Bukin ◽  
Vladimir Grigorievich Bukin
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Flow Boiling ◽  
Working Fluid ◽  
Transfer Coefficients ◽  
Two Phase ◽  
Pipe Length ◽  
Heat Transfer Coefficients

The paper presents the results of an experimental study of the effect of oil on the heat transfer rate at boiling of mixed refrigerant R406A. Since the air conditioning system is not a pure refrigerant, but a mixture of oil with a concentration of up to 8%, such an amount of oil affects both hydrodynamics and heat exchange in the evaporators. The experimental work covers the entire range of regime parameters typical for these systems. There is shown the process of changing oil concentration in the pipe, as the working fluid boils, proving that most of the oil pipe does not impair the heat exchange in the course of two-phase flow boiling. Different modes of refrigerant R406A boiling dynamics have been defined, and each mode is given a quantitative assessment in terms of the effects of the oil and explaining of this effect on the fluid flow and heat transfer based on visual observations and the experiment results. The main factor of the effect is the freon-oil foam, which increases the proportion of the wetted surface in the wave and stratified modes and the heat transfer rate to 30%. A comparison of the heat transfer coefficients both in the cross section and along the pipe length has been performed, showing that the maximum change in heat transfer occurs in the upper part of the surface due to developing a dry wall on it and wetting it with freon-oil foam. A comparison of the heat transfer rate of pure refrigerant R406A has been done; the presence of oil in it shows that the effect of oil is complex and ambiguous. Calculation and criterion dependences for calculation of heat transfer coefficients in different modes have been proposed.

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