Energy characteristics of changing the flow regime of the heat-carrier in the inter-plate channels of heat-exchange apparatus

1986 ◽  
Vol 22 (5) ◽  
pp. 202-203
Author(s):  
N. M. Stoyanov
Keyword(s):  
Heat Exchange ◽  
Flow Regime ◽  
Heat Carrier ◽  
Energy Characteristics ◽  
Exchange Apparatus

scholarly journals POLYMERS AND PLASTIC USE FOR THE HEAT-EXCHANGE EQUIPMENT (REVIEW)

2020 ◽  
pp. 59-71
Author(s):  
I.O. Mikulionok
Keyword(s):  
Heat Exchange ◽  
Heat Exchangers ◽  
Polymeric Materials ◽  
Strength Properties ◽  
Polymers And Plastics ◽  
Heat Exchange Equipment ◽  
Coefficient Of Heat Conductivity ◽  
Exchange Apparatus ◽  
Polymer Type

The possibility of use of the heat-exchangers in whole or in part manufactured with use of polymers and plastics is considered. Despite obvious, at first sight, inexpediency of use of polymeric materials in the heat-exchange equipment (low coefficient of heat conductivity, and also low, in comparison with metals, the strength properties of the majority of the most widespread polymers), «polymeric» heat-exchangers find application in various areas of the industry more and more surely. Classification of heat-exchange apparatuses which constructive elements are executed with use of polymeric materials is proposed. The following signs are the basis for classification: polymer type, a type of polymer meric material, type of the heat-exchange apparatus (a form of heat-exchange elements), reliance on polymeric materials in apparatuses, motion freedom of polymeric heat-exchange elements, level of assembly of a design, and also diameter of tubular elements. Critical analysis the most characteristic designs developed by domestic and foreign designers and inventors is carried out. Ref. 21, Fig. 13.

Numerical Study of Magnetic Field Influence on Three-Dimensional Flow Regime and Combined-Convection Heat Exchange Within Concentric and Eccentric Rotating Cylinders

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Javad Sodagar-Abardeh ◽  
Payam Nasery ◽  
Ahmad Arabkoohsar ◽  
Mahmood Farzaneh-Gord
Keyword(s):  
Magnetic Field ◽  
Heat Exchange ◽  
Flow Regime ◽  
Axial Magnetic Field ◽  
Numerical Study ◽  
Outer Cylinder ◽  
Three Dimensional ◽  
Convection Heat ◽  
Combined Convection ◽  
Number Variation

Abstract The forced and natural flows of fluid within an annulus caused by the rotation of cylinders and temperature differences of the inner and outer walls are observed in various engineering applications. In this research, the laminar flow regime and mixed convection inside a ring-shaped horizontal concentric and eccentric space for an incompressible fluid are studied in the existence of an axial magnetic field. The present work is the first effort to investigate the influence of a magnetic field on flow and combined-convection heat exchange characteristics within an annulus with a cold outer cylinder and an inner hot cylinder. Here, the properties of the flow and heat transfer characteristics are studied using the finite volume method. Numerical procedures are mainly investigated for recognizing the influence of Hartmann number (in the range of 0 ≤ Ha ≤ 100), as the representative of the magnetic force, on velocity components, Nusselt number, streamlines, and isothermal lines. One of the notable effects is that when Ha number increases, it will reduce the vorticity of the fluid and buoyancy forces. As a result, streamlines and isothermal lines can be seen more constant as regular concentric circles. A rise in Ha number decreases the range of local Nu number variation for both cylinders. The average Nu number for the outer and inner cylinders has different trends when Ha number increases. Taking concentric cylinders as an example, this parameter for the inner and the outer cylinders increases and decreases by about 1.2 and 1.6, respectively.

Heat exchange apparatus of low thermal conductivity plastics

1969 ◽  
Vol 5 (8) ◽  
pp. 650-651
Author(s):  
S. M. Lukomskii ◽  
D. F. Kagan ◽  
M. Ya. Nemlikher
Keyword(s):  
Thermal Conductivity ◽  
Heat Exchange ◽  
Low Thermal Conductivity ◽  
Exchange Apparatus

scholarly journals Analysis Of Three Layer Concentric Tube Heat Exchange Using Mathematic Modeling

2021 ◽  
Vol 10 (3) ◽  
pp. 86-92
Author(s):  
Rinaldy Valendry
Keyword(s):  
Mathematical Modeling ◽  
Heat Exchange ◽  
Coming Out ◽  
Theoretical Calculations ◽  
Fluid Temperature ◽  
Modeling Methods ◽  
Mathematic Modeling ◽  
Cold Fluid ◽  
Theory Calculation ◽  
Exchange Apparatus

A three-channel concentric pipes heat exchanger is a development or improvement of a two-channel concentric heat exchange apparatus. This study was conducted to determine the output temperature of each channel, and compare the results of theoretical calculations using mathematical modeling of experimental results conducted in the field. So that obtained difference of value between result of experiment to result of theory calculation. In this study have 3 variations of temperature data that is 50 °C, 55°C, and 60 °C with two streams namely CounterFlow and PararellFLow and discharge 2.5 l/minute, while cold fluid with 25 °C discharge 1.5 l/minute. From the above analysis it can be concluded that the temperature of the hot fluid coming out of the APK in the experiment tends to be higher than the temperature of the hot fluid coming out of the APK on theoretical calculations of mathematical modeling methods. Meanwhile, the cold cold fluid temperature coming out of the APK in experimental tends to be lower than the temperature of the cold fluid coming out of the APK on theoretical calculations of mathematical modeling methods.

A model heat-exchange apparatus for the investigation of fouling of stainless steel surfaces by milk I. Deposit formation at 100 °C

1989 ◽  
Vol 56 (2) ◽  
pp. 201-209 ◽  
Author(s):  
Carole L. Foster ◽  
Michel Britten ◽  
Margaret L. Green
Keyword(s):  
Stainless Steel ◽  
Heat Exchange ◽  
Time Course ◽  
Small Scale ◽  
Lag Phase ◽  
Stainless Steel Surface ◽  
Deposit Formation ◽  
Factors Affecting ◽  
Steel Surfaces ◽  
Exchange Apparatus

SummaryA model heat-exchange apparatus was used to investigate the factors affecting deposit formation from milk on a stainless steel surface at 100 °C. The structure and composition of the deposits were determined by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and chemical analysis after solution in alkali. The effects of changing the pH, preheating and skimming of the milk were similar to those observed in a small-scale continuous ultra high temperature plant. The time course of deposit formation showed that a lag phase did not occur, but the deposit which formed after more than 45 min was more porous than that formed after shorter times. Most (50–90%) of the fresh deposit was readily removed by sonication, leaving a sublayer richer in minerais than the original. The results provide evidence for the two-layer model for deposit formation proposed by Tissier & Lalande (1986).

scholarly journals Icing control model and algorithm for wasteheat exchangers of ventilation systems

2018 ◽  
Vol 194 ◽  
pp. 01004
Author(s):  
Аndrew Arbatskiy ◽  
Аndrew Garyaev ◽  
Vasiliy Glasov
Keyword(s):  
Mathematical Model ◽  
Heat Exchange ◽  
Heat Exchangers ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Control Model ◽  
Humid Air ◽  
Exchange Apparatus ◽  
Ice Control

Currently, ice control on various heat exchangers to be used for waste heat recovery of discharge air is a rather topical subject because ice building is a factor to reduce efficiency of heat recovery. In such systems, icing always takes place on the side of humid discharge air, with a background of heat exchange between inlet air at temperatures of -30°C and below, and discharge air. To effectively prevent this, it is required to find solutions to problems as follows: study a mechanism of ice building on heat exchange surfaces when interacting with humid air; determine engineering methods to prevent icing, for each type of heat-exchange apparatus, and check efficiency of their operation; develop a mathematical model of ice growth on heat exchange surfaces to enable to vary key parameters (both geometrical and algorithmical ones), determined beforehand, and engineering means aimed at icing prevention.

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