4869314 Heat exchanger with secondary and tertiary heat exchange surface

1990 ◽  
Vol 10 (3) ◽  
pp. xviii
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Heat Exchange Surface ◽  
Exchange Surface

Thermodynamic Estimate of Minimal Dissipation for Heat Exchange System

2008 ◽  
Author(s):  
Andrei A. Akhremenkov ◽  
Anatoliy M. Tsirlin ◽  
Vladimir Kazakov
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Heat Load ◽  
Point Of View ◽  
Exchange System ◽  
Heat Exchange System ◽  
Heat Exchange Surface ◽  
Minimal Dissipation ◽  
The Difference ◽  
Exchange Surface

In this paper we consider heat exchange system from point of view of Finite-time thermodynamics. At first time the novel estimate of the minimal entropy production in a general-type heat exchange system with given heat load and fixed heat exchange surface is derived. The corresponding optimal distribution of heat exchange surface and optimal contact temperatures are also obtained. It is proven that if a heat flow is proportional to the difference of contacting flows’ temperatures then dissipation in a multi-flow heat exchanger is minimal only if the ratio of contact temperatures of any two flows at any point inside heat exchanger is the same and the temperatures of all heating flows leaving exchanger are also the same. Our result based on those assumptions: 1. heat transfer law is linear (17); 2. summary exchange surface is given; 3. heat load is given; 4. input tempretures for all flows are given; 5. water equivalents for all flows are given.

Experimental study of the solid fouling effect on the air-cooled apparatus characteristics

2021 ◽  
Vol 12 (1) ◽  
pp. 1-9
Author(s):  
Larisa Morozyuk ◽  
Viktoriia Sokolovska-Yefymenko ◽  
Andrii Moshkatiuk ◽  
Bohdan Hrudka
Keyword(s):  
Experimental Study ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Experimental Sample ◽  
Qualitative Composition ◽  
Aerodynamic Properties ◽  
Study Results ◽  
Heat Exchange Surface ◽  
Air Condenser ◽  
Exchange Surface

External fouling on the heat exchange surface of air-cooled apparatus are formed during operation, which leads to a significant increase in energy consumption and deviations from the optimal operating mode of the entire system. This phenomenon is a problem for all energy conversion systems. This paper presents the experimental study results of a complex of a commercial cooled object with real fouling on the air condenser surface. To study the effect of fouling, an experimental bench was developed – a single-stage refrigerating machine that provides cold supply to a thermostatic chamber. Three types of fouling were used: sand, fluff and dust. Fouling were picked from the operating condensers and identical in the type of heat exchange surface to the experimental sample. With a change in the quantitative and qualitative composition of the fouling, the air condenser thermal and aerodynamic characteristics and the energy efficiency of the machine as a whole were determined. The experiment showed that at maximum fouling of the heat exchange surface with sand and fluff, air movement stops. This means that at a certain thickness of sand and fluff layer, an air impermeable dense structure is formed. Dust with the same form of filling the free space for the flow remains permeable to air. Experiments showed that the qualitative composition of the fouling is the main factor that determines the heat exchanger performance. It was found that from the experimental set of fouling, roadside dust has the greatest negative effect on the condenser characteristics and the machine as a whole. The aerodynamic properties of the heat exchanger depend to some extent on the qualitative composition of the fouling. As a conclusion, it was suggested that the process nature of air flow passing through the investigated fouling can be described as gas flows in porous media.

scholarly journals Geothermal heat use to eliminate hydrate formations in oil deposit injection wells

2021 ◽  
Vol 230 ◽  
pp. 01019
Author(s):  
Мykhailo Fyk ◽  
Volodymyr Biletskyi ◽  
Madjid Аbbood ◽  
Fabris Аnzian
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Oil Field ◽  
Injection Well ◽  
Mathematical Apparatus ◽  
Joint Work ◽  
Injection Wells ◽  
Geothermal Heat ◽  
Heat Exchange Surface ◽  
Exchange Surface

The article is devoted to an actual issue: the development of internal downhole heat exchangers technology to combat hydration in injection wells. Purpose: development of conceptual solutions for the use of geothermal coolant in the internal well heat exchanger of the injection well. A scheme of an internal downhole heat exchanger with a geothermal heat carrier has been developed, and includes a supply line of a geothermal carrier through the heat exchange surface of the injection well into the productive reservoir of the oil field. The scheme provides targeted utilization of thermobaric energy of a geothermal source to combat hydration in the injection well. A mathematical apparatus for describing the process of heat utilization and heat exchange in injection well is proposed. It is established that the capacity of one geothermal well discovered at the oil depths in the Dnipro-Donetsk basin is sufficient to eliminate hydration in 1-3 injection wells, and determines the feasibility of their joint work.

scholarly journals EXPERIMENTAL STUDIES OF THERMAL TRANSMISSION THROUGH A MOBILE HEAT EXCHANGE SURFACE

2020 ◽  
Vol 2018 (1) ◽  
pp. 28-31
Author(s):  
Borislav Kustov ◽  
Mihail Gerasimchuk
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Flow Rate ◽  
Experimental Studies ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Heat Exchange Surface ◽  
Thermal Transmission ◽  
Exchange Surface

Experimental studies of heat transfer in a heat exchanger of the "pipe-in-pipe" type with a rotating tube have been performed. It is established that in the investigated range of hot coolant flow rate, the rotation of the pipe makes it possible to increase the values of the heat transfer coefficients by 19-28%.

scholarly journals Design of a Heat Exchanger Made of Gravity Heat Pipes with an Enlarged Heat Exchange Surface for Heat Dissipation from the Electrical Cabinet

2020 ◽  
Vol 328 ◽  
pp. 01012
Author(s):  
Patrik Nemec
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Forced Convection ◽  
Heat Dissipation ◽  
Electronic Components ◽  
Heat Management ◽  
Heat Exchange Surface ◽  
Exchange Surface ◽  
Design Construction

Due to the great progress in the electronics industry, heat management in electronic components is becoming a serious and important problem. Cooling of electronic components ensures a lower occurrence of failure of elements, longer service life of the device, protection against overheating of elements, further prevents malfunction of the device and loss of heat. In many cases, heat dissipation by natural convection is often insufficient. Heat dissipation by forced convection is effective, but it carries the risk of clogging the interior of the electrical cabinet with dust, which can negatively affect the functionality of the electrical elements over time. One of the possibilities of efficient heat dissipation from the electrical cabinet without forced convection is by means of heat pipe technology, which uses a phase change of the working substance for heat transfer. The article deals with the design, construction and experimental determination of the performance of gravity heat tubes with an increased heat exchange area suitable for the design of an electrical cabinet heat exchanger.

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.

Computer simulation of the reliability of the heat exchange surface of the steam turbine condenser

2022 ◽  
pp. 1748006X2110672
Author(s):  
Krzysztof Bernard Łukaszewski
Keyword(s):  
Heat Exchange ◽  
Steam Turbine ◽  
Cooling Water ◽  
Operating Conditions ◽  
Time Varying ◽  
Turbine Condenser ◽  
Heat Exchange Surface ◽  
Steam Turbine Condenser ◽  
The Relationship ◽  
Exchange Surface

The aim of the article is to demonstrate the relationship between the adaptive regulation of the heat exchange surface to specific operating conditions of a steam turbine condenser and the reliability and availability of this surface in a specific period of time. The article exemplifies the relationship between the settings of the condenser heat exchange surface and the resulting changes in the reliability structures of this surface. The method of creating a mathematical model of reliability estimation, which is characterized by the variability of the reliability structures of the heat exchange surface in relation to specific operating conditions in a specific period of time, was indicated. Then, exemplary simulations of the adaptation of reliability structures of specific pipe systems constituting the condenser’s heat exchange surface to specific processes of operation of this condenser are presented. The simulations refer to the time-varying thermal loads of the condenser, the time-varying mean thickness of the sediments, and changes in the temperature of the cooling water at the point of its intake over time. The adaptation of certain reliability structures consists in the adaptation of specific systems of pipes through which the cooling water flows to the currently existing operating conditions of the condenser in order to maintain the desired reliability of the heat exchange surface for a specified time. This is done by enabling or disabling the flow of cooling water through a given number of pipes in specific systems under given operating conditions. On the basis of computer simulations, the reliability functions, and the availability functions of the subsystem under consideration were estimated.

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