TECHNOLOGICAL PARAMETERS OF THE COOLING MODE OF POLYMER INSULATION OF POWER CABLES

Introduction. The cooling mode of polymer insulation after application to the extruder is one of the main factors determining cable performance. Theoretically, it is ideal to cool the insulation when the temperature of the cooling medium is equal to the melting point of the insulation material: in t...

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Autores principales:	G. V. Bezprozvannych, I. A. Mirchuk, A. G. Kyessayev
Formato:	article
Lenguaje:	EN RU UK
Publicado:	National Technical University "Kharkiv Polytechnic Institute" 2019
Materias:	cooling mode polyethylene insulation thermal equivalent circuit discrete resistive equivalent circuit method transient mode nodal potentials method system of linear algebraic equations cooling bath length Electrical engineering. Electronics. Nuclear engineering TK1-9971
Acceso en línea:	https://doaj.org/article/1c9087bbf1334b65b1fcf9dbbad92ae8
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spelling	oai:doaj.org-article:1c9087bbf1334b65b1fcf9dbbad92ae82021-12-02T16:27:54ZTECHNOLOGICAL PARAMETERS OF THE COOLING MODE OF POLYMER INSULATION OF POWER CABLES10.20998/2074-272X.2019.3.072074-272X2309-3404https://doaj.org/article/1c9087bbf1334b65b1fcf9dbbad92ae82019-06-01T00:00:00Zhttp://eie.khpi.edu.ua/article/view/2074-272X.2019.3.07/171133https://doaj.org/toc/2074-272Xhttps://doaj.org/toc/2309-3404Introduction. The cooling mode of polymer insulation after application to the extruder is one of the main factors determining cable performance. Theoretically, it is ideal to cool the insulation when the temperature of the cooling medium is equal to the melting point of the insulation material: in this case, the probability of formation of voids in the insulation is less. The cooling process is usually not subject to stringent requirements, since most insulating materials allow for quite sharp cooling. The exception is polyethylene, which requires gradual cooling. When the insulation is cooled in a cooling bath, the temperature decrease starts from the surface. In this regard, the cooling of the insulation of polyethylene is carried out in steps to a temperature at which the cooled extruded insulation will not be deformed or damaged on the receiving drum. Polyethylene is characterized by a large value of thermal expansion coefficient, the maximum value of which is in the temperature range (90-125) °C. As a result, there is an uneven reduction in the volume of the upper and inner insulation layers, especially for cables with a considerable insulation thickness. The rapid cooling of polyethylene leads to the formation of cracks, air inclusions both between the insulation and the conductive core, and in the layers located near the core. Purpose. The substantiation of the technological parameters of the cooling mode of power cables based on the calculation of the thermal equivalent circuit of a conductive core insulated with polyethylene in transient thermal mode. Methodology. The calculation of the temperature distribution in the thickness of extruded polyethylene insulation at different points in time, depending on the temperature of the cooling water, is made by the method of electrothermal analogies. There is a transition from the thermal equivalent circuit of power cables to the equivalent circuit of the discrete resistive equivalent circuit method, which is calculated using the nodal potential method. As a result of solving a three-diagonal system of linear algebraic equations by sweeping and finding at each discretization step (time step) thermal power fluxes in the branches of the thermal equivalent circuit, the temperature in the thermal capacitances determines the temperature in each insulation layer. Practical value. The duration of the transition process, corresponding to the achievement of the same temperature throughout the thickness of the insulation, can be considered as a criterion in determining the length of the cooling bath sections depending on the extrusion (reception) rate. G. V. BezprozvannychI. A. MirchukA. G. KyessayevNational Technical University "Kharkiv Polytechnic Institute"articlecooling modepolyethylene insulationthermal equivalent circuitdiscrete resistive equivalent circuit methodtransient modenodal potentials methodsystem of linear algebraic equationscooling bath lengthElectrical engineering. Electronics. Nuclear engineeringTK1-9971ENRUUKElectrical engineering & Electromechanics, Iss 3, Pp 44-49 (2019)
institution	DOAJ
collection	DOAJ
language	EN RU UK
topic	cooling mode polyethylene insulation thermal equivalent circuit discrete resistive equivalent circuit method transient mode nodal potentials method system of linear algebraic equations cooling bath length Electrical engineering. Electronics. Nuclear engineering TK1-9971
spellingShingle	cooling mode polyethylene insulation thermal equivalent circuit discrete resistive equivalent circuit method transient mode nodal potentials method system of linear algebraic equations cooling bath length Electrical engineering. Electronics. Nuclear engineering TK1-9971 G. V. Bezprozvannych I. A. Mirchuk A. G. Kyessayev TECHNOLOGICAL PARAMETERS OF THE COOLING MODE OF POLYMER INSULATION OF POWER CABLES
description	Introduction. The cooling mode of polymer insulation after application to the extruder is one of the main factors determining cable performance. Theoretically, it is ideal to cool the insulation when the temperature of the cooling medium is equal to the melting point of the insulation material: in this case, the probability of formation of voids in the insulation is less. The cooling process is usually not subject to stringent requirements, since most insulating materials allow for quite sharp cooling. The exception is polyethylene, which requires gradual cooling. When the insulation is cooled in a cooling bath, the temperature decrease starts from the surface. In this regard, the cooling of the insulation of polyethylene is carried out in steps to a temperature at which the cooled extruded insulation will not be deformed or damaged on the receiving drum. Polyethylene is characterized by a large value of thermal expansion coefficient, the maximum value of which is in the temperature range (90-125) °C. As a result, there is an uneven reduction in the volume of the upper and inner insulation layers, especially for cables with a considerable insulation thickness. The rapid cooling of polyethylene leads to the formation of cracks, air inclusions both between the insulation and the conductive core, and in the layers located near the core. Purpose. The substantiation of the technological parameters of the cooling mode of power cables based on the calculation of the thermal equivalent circuit of a conductive core insulated with polyethylene in transient thermal mode. Methodology. The calculation of the temperature distribution in the thickness of extruded polyethylene insulation at different points in time, depending on the temperature of the cooling water, is made by the method of electrothermal analogies. There is a transition from the thermal equivalent circuit of power cables to the equivalent circuit of the discrete resistive equivalent circuit method, which is calculated using the nodal potential method. As a result of solving a three-diagonal system of linear algebraic equations by sweeping and finding at each discretization step (time step) thermal power fluxes in the branches of the thermal equivalent circuit, the temperature in the thermal capacitances determines the temperature in each insulation layer. Practical value. The duration of the transition process, corresponding to the achievement of the same temperature throughout the thickness of the insulation, can be considered as a criterion in determining the length of the cooling bath sections depending on the extrusion (reception) rate.
format	article
author	G. V. Bezprozvannych I. A. Mirchuk A. G. Kyessayev
author_facet	G. V. Bezprozvannych I. A. Mirchuk A. G. Kyessayev
author_sort	G. V. Bezprozvannych
title	TECHNOLOGICAL PARAMETERS OF THE COOLING MODE OF POLYMER INSULATION OF POWER CABLES
title_short	TECHNOLOGICAL PARAMETERS OF THE COOLING MODE OF POLYMER INSULATION OF POWER CABLES
title_full	TECHNOLOGICAL PARAMETERS OF THE COOLING MODE OF POLYMER INSULATION OF POWER CABLES
title_fullStr	TECHNOLOGICAL PARAMETERS OF THE COOLING MODE OF POLYMER INSULATION OF POWER CABLES
title_full_unstemmed	TECHNOLOGICAL PARAMETERS OF THE COOLING MODE OF POLYMER INSULATION OF POWER CABLES
title_sort	technological parameters of the cooling mode of polymer insulation of power cables
publisher	National Technical University "Kharkiv Polytechnic Institute"
publishDate	2019
url	https://doaj.org/article/1c9087bbf1334b65b1fcf9dbbad92ae8
work_keys_str_mv	AT gvbezprozvannych technologicalparametersofthecoolingmodeofpolymerinsulationofpowercables AT iamirchuk technologicalparametersofthecoolingmodeofpolymerinsulationofpowercables AT agkyessayev technologicalparametersofthecoolingmodeofpolymerinsulationofpowercables
_version_	1718383979426480128

TECHNOLOGICAL PARAMETERS OF THE COOLING MODE OF POLYMER INSULATION OF POWER CABLES

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