Экспериментально-аналитические исследования взаимосвязи горючести материалов и параметров источников зажигания в гермобарокамерах с обогащенными кислородом средами и при повышенном давлении

Abstract

The results are presented related to the experimental and analytical studies of the relationship between the combustibility of materials and the parameters of ignition sources in the equipment with oxygen-enriched media and at an elevated pressure. It is shown that when materials used in the thermal chambers are heated, the temperature of spontaneous ignition increases significantly near combustion limits in terms of oxidant concentration and pressure, and a regime occurs, in which gasification of the sample can take place without ignition. The nature of the ignition of the insulation of the wire and materials depends on the current load. The time from the beginning of the short circuit to the beginning of the pyrolysis process, i.e. before the appearance of smoke, according to the calculations, is inversely dependent on the square of the current strength. The ignition delay time of the materials in the cable composition tends to decrease with increasing current. Moreover, at the same current density, the ignition delay time of materials from a single wire is less than that of a cable even with a current load of four wires. This circumstance and the patterns obtained for the ignition of materials from a single wire allow to conclude that the response time of the current protection for cables can be selected based on the delay time for the ignition of materials from a single wire.