Optimization of geometric parameters and analysis of exergy efficiency of heat recovery units glass furnaces

2021 ◽  
pp. 5-17
Author(s):  
N. Fialko ◽  
◽  
A. Stepanova ◽  
R. Navrodska ◽  
S. Shevchuk ◽  
...  
Keyword(s):  
Heat Exchange ◽  
Heat Exchangers ◽  
Heat Recovery ◽  
Glass Melting ◽  
Exergy Efficiency ◽  
Geometric Parameters ◽  
Hot Water ◽  
Air Heating ◽  
Heat Exchange Surface ◽  
Exchange Surface

The paper presents the results of optimization of the geometric parameters of the heat exchange surface of water and air-heating heat exchangers of glass-making furnaces and an analysis of their exergy efficiency. Ensuring the efficient operation of heat recovery units in various thermal circuits is an urgent problem of heat power engineering. The aim of the work is to establish the optimal areas of the geometric parameters of the heat exchange surface of heat recovery units of glass-melting furnaces and to analyze their exergy efficiency. The paper presents the results of solving the tasks necessary to achieve the goal: - using statistical methods for planning the experiment, determine the levels of variation of the parameters of the geometric surface of heat transfer for the heat recovery units under study and calculate the values of the criteria for evaluating the efficiency at the points of the central orthogonal compositional plan; - to obtain the regression equations for the investigated heat exchangers, to determine the optimal areas of change in the geometric parameters of the heat exchange surface and the corresponding exergy efficiency criteria. To determine the optimal areas of geometric parameters of the heat exchange surface, a complex methodology is used based on the methods of exergy analysis and statistical methods of the theory of experiment planning. It has been established that when designing heat recovery schemes for heating water in heat supply systems and for heating blast air, heat recovery units with the following values of the areas of variation of the geometric parameters of the heat exchange surface can be used: - the values of the area of variation of the distance between the panels for heat recovery units with a staggered and corridor arrangement of pipes in a bundle s1 = 58.0-62.0 mm. - the values of the areas of change in the diameter of pipes for a hot water heat exchanger with a corridor arrangement of pipes d = 41.0-43.0 mm and for an air heating heat exchanger with a staggered and corridor arrangement of pipes d = 29.0-31.0 mm. - the use of the values of the ranges of change of other parameters is carried out taking into account additional technological factors. It has been established that the exergy efficiency of hot water heat recovery units is in all cases higher than the exergy efficiency of air heating units. For hot water heat exchangers, the values of exergy criteria are lower than for air heating ones: k – 2.0 times, ε – by 7.5%, m0 – 1.9 times. The expediency of using the investigated heat recovery units in heat recovery circuits of glass melting furnaces has been established, taking into account the results obtained and in the presence of certain technological factors. The results obtained and further developments in the field of optimization of the operating parameters of heat recovery units for glass-melting furnaces will provide an increase in the efficiency of heat recovery equipment for power plants.

scholarly journals About mathematical modeling of aerodynamic characteristics in devices with a leakage of the impact systems of plane-parallel streams on the heat exchange surface

2018 ◽  
Vol 170 ◽  
pp. 03024
Author(s):  
Larisa Haritonova ◽  
Valery Azarov ◽  
Igor Stefanenko
Keyword(s):  
Heat Exchange ◽  
Heat Exchangers ◽  
Aerodynamic Resistance ◽  
Aerodynamic Characteristics ◽  
Plane Parallel ◽  
Heat Exchange Surface ◽  
Parallel Streams ◽  
The Impact ◽  
The Mathematical Model ◽  
Exchange Surface

The article is devoted to the development of the general aerodynamic theory in case of a leakage by the systems of plane-parallel impact jets on the plane heat exchange surface [1-2]. An analytical generalization of data on aerodynamic resistance with the blowout of flat surface by the system of the plane-parallel impact jets was implemented. These data were obtained as a result of the application of mathematical theory of planning an experiment. The equations of regression are the mathematical model of process. Functional dependences between the constructive factors and the regime parameters of these first obtained experimental dependences on aerodynamic resistance in the jet heat exchangers with the leakage of air in the form of the system of plane-parallel jets were established. Results of work can be used in developing of different methods of calculation for various new designs of highly effective heat exchangers or their optimization for various branches.

Mathematical Models of the Ocurved Spring Tubes Surfaces

2019 ◽  
Vol 16 (11) ◽  
pp. 4554-4559 ◽  
Author(s):  
Valeriya Leonidovna Vorontsova ◽  
Alfiya Gizzetdinovna Bagoutdinova ◽  
Almaz Fernandovich Gilemzianov
Keyword(s):  
Heat Exchange ◽  
Mathematical Models ◽  
Heat Exchangers ◽  
Coil Spring ◽  
Compact Heat Exchangers ◽  
Curved Channels ◽  
Exchange Processes ◽  
Heat Exchange Surface ◽  
The Creation ◽  
Exchange Surface

One of the ways to intensify heat exchange processes is the creation of compact heat exchangers with a developed heat exchange surface. It is known that coil-type channels provide a developed heat exchange surface and belong to one of the most efficient and technological designs of heat exchange elements. In this regard, the authors proposed a small-size heat exchanger of the “pipe in pipe” type with an internal coil spring-twisted channel, and the authors of the proposed article developed mathematical models describing the heat-exchange surfaces of pipes of complex configurations, including coil spring-coiled channels. The equations of heat transfer surfaces are written in vector-parametric form based on the fundamental principles of analytical and differential geometry. In order to verify the adequacy and visualization of the written equations, surfaces were constructed using the Matlab application software package. The proposed mathematical models can be used in computer simulation of hydrodynamic processes during the flow of liquid media in curved channels, which will allow to explore and further optimize their internal geometry by changing the parameters of the equations. This work is a continuation of research on the creation of efficient heat exchangers.

scholarly journals Efficiency of different types gas heaters for chimney anticorrosion protection systems of boiler plants

2020 ◽  
pp. 5-16
Author(s):  
N. Fialko ◽  
◽  
A. Stepanova ◽  
R. Navrodska ◽  
S. Shevchuk ◽  
...  
Keyword(s):  
Heat Exchange ◽  
Geometric Parameters ◽  
Planning Theory ◽  
Water Heating ◽  
Anticorrosion Protection ◽  
Gas Heating ◽  
Heat Exchange Surface ◽  
Different Types ◽  
Exchange Surface ◽  
Plate Type

The of researches results of exergy efficiency and optimization of parameters of different types gas heaters by used for anticorrosion protection of gas exhaust ducts of heating boiler plants equipped with exhaust gas heat recovery systems are presented. The choice of a complex technique for analyzing the efficiency of gas heaters, which makes it possible to obtain functional dependences of the selected efficiency criteria on the geometric parameters of the heat exchange surface of gas heaters for solving optimization problems is substantiated. Such a technique can be a technique based on exergy methods and statistical methods of experiment planning theory. This technique by an insignificant number of initial parameters required for calculation, and by the simplicity of calculation and analytical methods for obtaining exergy characteristics is characterized. The work considered three types of gas heaters: water-heating (water-gas) and two gas-heating (gas-gas) pipe and plate type. The heat exchange surface of the water-heating gas heater is assembled from transverse-finned bimetallic (steel base and aluminum fins) pipes, gas-heating pipe-type - from steel pipes with circular turbulators flow, and gas-heating plate-type - from smooth steel plates. The general system of balance equations used in this complex technique, and also its the basic stages, are presented. It is noted that the choice of complex criteria for assessing the efficiency of gas heaters is carried out according to the degree of sensitivity of the criteria to changes in the operating and geometric parameters of gas heaters. Using the proposed sensitivity coefficient, the degree of sensitivity of different efficiency criteria has been analyzed and it has been established that one of the most sensitive to changes in the geometric parameters of the heat exchange surface of gas heaters is the heat-exergy criterion. The results of the corresponding calculations for each of the three gas heaters are presented. It has been established the most exergetically effective is a water-heating gas heater, followed by gas-heating gas heaters, of plate and tube types respectively.

Analysis of the Performance for a Group-Annulus Type Oil-Fired Boiler

2010 ◽  
Vol 97-101 ◽  
pp. 2921-2924
Author(s):  
Hui Lan Huang ◽  
Gang Li
Keyword(s):  
Heat Exchange ◽  
Thermal Stresses ◽  
High Ratio ◽  
Hot Water ◽  
Heat Exchange Surface ◽  
Radiation Heat Exchange ◽  
Exchange Structure ◽  
Tube Type ◽  
Improved Design ◽  
Exchange Surface

To overcome the shortcomings of the traditional hot-water boilers, a oil-fired hot water boilers is improved design for a group-annulus structure. A finished product boiler is thermodynamic analyzed with the tested heat generation amount equivalent to 350 kW. The results indicate that the unique heat exchange structure of group-annulus type hot-water boilers can reduce thermal stresses and intensify convection heat exchange. The radiation heat-exchange space is 2 times more than that of the shell-tube boiler, and surfaces inside the furnace are comparatively large. Compared with shell-tube type boilers, the group-annulus type boilers is made a distinction with small volume and heat-exchange surface area, low metal consumption and high ratio of performance to cost under the same total heat-exchange quantity.

scholarly journals Low-Reynolds Simulation of Heat Transfer in Turbulent Flow in a Flat Channel with Symmetrically Arranged Turbulators on Both Sides of the Channel

2020 ◽  
Vol 4 (1) ◽  
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Cross Section ◽  
Heat Exchangers ◽  
Thermal Loading ◽  
Flat Channel ◽  
Heat Transfer Intensification ◽  
Heat Flows ◽  
Heat Exchange Surface ◽  
Exchange Surface

Widespread use in modern heat exchangers and apparatus received heat exchangers, where the channels have a cross-section, different from the round tubes, in a particular case, flat channels, where heat is not produced by means of a full surface to be washed. The thermal loading of a flat channel can be asymmetric, since the heat flows on different surfaces can be unequal, namely: flat channels with one-way heating or with two-way heating with unequal heat flows. In order to ensure the compactness of heat exchange devices and heat exchange apparatuses, heat transfer intensification is used, which in flat channels is achievable by two main methods: the development of the heat exchange surface and turbulence of the flow in the channels.

scholarly journals CONSTRUCTIVE DESIGN OF HEAT EXCHANGERS "TUBE-IN-TUBE" (REVIEW)

2020 ◽  
pp. 63-74
Author(s):  
I.O. Mikulionok
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Heat Exchangers ◽  
Critical Analysis ◽  
Vortex Generators ◽  
Small Surface ◽  
Heat Exchange Surface ◽  
Main Defect ◽  
Exchange Surface

Advanced designs of one of the simplest and reliable heat-exchange apparatuses for processing of various liquid and gaseous environments – heat exchangers "tube-in-tube" are considered. New designs in the majority a case eliminate the main defect of classical heat exchangers "tube-in-tube" – a small surface of a heat transfer. However increase in a heat exchange surface usually significantly complicates production and/or operation (including repair) heat exchangers. Classification of the heat exchange devices "tube-in-tube" is proposed: The following signs are the basis for classification: assembly level, quantity of streams in channels, the design material nature, degree of mobility of heat exchange tubes, existence of vortex generators in channels, a form of external and/or internal tubes. The critical analysis of the most characteristic designs of the heat exchangers "tube-in-tube" developed by domestic and foreign designers and inventors is made. Bibl. 17, Fig. 21.

scholarly journals FEATURES OF CALCULATION OF ON-BOARD HEAT EXCHANGERS

2021 ◽  
pp. 52-59
Author(s):  
U. L. Moshentsev ◽  
А. А. Gogorenko
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Heat Exchangers ◽  
Cooling System ◽  
Transfer Coefficients ◽  
Design Problems ◽  
Average Value ◽  
Heat Transfer Coefficients ◽  
Heat Exchange Surface ◽  
Exchange Surface

Aspects of designing an onboard heat exchangers for the cooling system of the ship's power plant are considered. Such heat exchangers must be designed in accordance with the classical foundations of the theory and calculation of heat exchangers. At the same time, the key design points are considered by well-known sources in a separate setting related to the peculiarities of their consideration as specific elements of the theory. In this regard, they are not united by a single system necessary for their use in specific design problems. Accordingly, the paper highlights, concretizes and refines the parameters of the formulas used in the computational problem. In particular, the calculation of the heat transfer coefficient from the seawater side is performed according to the formula that gives the average value of the coefficient for the vessel. The heat transfer coefficients from the side of the coolant of the inner loop are calculated according to the well-known formulas recommended for calculating heat transfer in channels of any shape. Attention is drawn to the fact that heat transfer from the hold side goes to the finned wall. In this regard, the heat transfer coefficients determined by the indicated formulas should be considered convective. The transition to the given values of the heat transfer coefficients should be carried out considering the efficiency of the finned heat exchange surface, which considers the uneven temperature of various sections of the heat exchange surface. The calculation of heat transfer was carried out considering possible surface contamination. The procedure for performing the calculation steps is proposed, as a result of which the dimensions and heat engineering parameters of the heat exchanger can be determined. It was found that the use of the considered proposals leads to results close to those recommended by authoritative sources. The above proposals do not contradict the experience of creating and designing such structures. The recommendations can be used for educational and practical purposes by those who design heat exchangers of similar designs.

Temperature control in a chemical reactor through variable area of the heat transfer surface. Simulation analysis

1982 ◽  
Vol 47 (2) ◽  
pp. 430-445
Author(s):  
Josef Horák ◽  
Zina Valášková
Keyword(s):  
Heat Exchange ◽  
Simulation Analysis ◽  
Batch Reactor ◽  
Chemical Reactor ◽  
Rate Of Change ◽  
Action Variable ◽  
Heat Exchange Surface ◽  
Relay With Hysteresis ◽  
Exchange Surface

An algorithm has been developed and on a mathematical model analyzed to stabilize the reaction temperature of a batch reactor. The reaction has been a zero-order one and the reactor has been operated in a instable operating point. The action variable is the heat exchange surface whose area is increased if the temperature is above, or decreased if the temperature is below the set point. The following two-point regulators have been studied: An ideal relay, a relay with hysteresis and an asymmetric PD relay. The effect has been discussed of the parameters of the regulators on the quality of regulation. Stability analysis has been made of the stationary switching cycles and the domains of applicability have been determined for individual regulators with respect to the rate of change of the area of heat exchange surface.

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