Розрахунок процесу термічного ураження залізобетонних опор струмами однофазного замикання на землю

Автор(и)

  • А. О. Квіцинський
  • О. В. Шеліманова

Анотація

UDC 536.21

CALCULATION OF THERMAL SHOCK OF REINFORCED CONCRETE PILLARS BY CURRENTS SINGLE-PHASE GROUND FAULT

A. KVITSYNSKYY, O. SHELIMANOVA

 

When single-phase ground fault (OZZ) concrete pillars can be heated to high temperatures (200 0 C and above), which causes thermal destruction of the pillars’ material. Therefore, the task of calculating of  changes over time in key indicators of thermal shock process of concrete pillars by currents of single-phase ground fault in networks with isolated neutral is relevant.

Assuming that the thermal destruction process can precede relatively quickly, heat exchange between the earth and the air and the diffusion of moisture in the ground will be ignored.

Buried in the ground part of the reinforced concrete pillars is replaced on the model - equivalent hemisphere. This will provide the same first approximation the current density at the surface of the reinforced concrete pillars and models and will consider the process of thermal destruction recesses of support as transient electro-dimensional process due to evenly distributed and variable time sources of heat. Characteristics of the reinforced concrete pillars buried in the ground (temperature and conductivity) will be considered the same.

Changing the resistance layer, which is located near concrete poles, causes a redistribution of power between the different layers of the earth and the ground temperature heating layers (Fig. 1). The nature of the process while significantly depends on the thermal characteristics of the ground (temperature characteristics - dependence of resistivity on temperature, initial values of temperature and humidity, specific heat capacity and thermal conductivity, moisture conductivity, etc.) and the value of current ground fault circuits.

Посилання

Правила технічної експлуатації електроустановок споживачів. – Х. : Форт, 2006. – 272 с.

Кутателадзе С. С. Теплопередача и гидравлическое сопротивление : справ. пособие / С. С. Кутателадзе. – М. : Энергоатомиздат, 1990. – 367 с.

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Опубліковано

2017-02-24

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