Оценка пожарного риска в технологическом оборудовании с электрическими нагревателями

Abstract

An important role in the field of fire prevention of the electrical installations, including electrical heating equipment, is played by the research and development of the risk-based engineering methods for assessing fire safety of the objects. It is also important to find economically sound ways to ensure it. Widespread use of the electrical heating equipment in the technological processes and a significant number of fires from heaters require a fire risk assessment considering power supply and technological process control systems. Current requirements for determining fire risk of the electrical heating equipment are not effective enough. According to the statistics, the electric heaters occupy one of the first places among the electrical equipment as a cause of fires. The article describes a methodology for assessing the probability of fire hazard modes during the operation of electrical heating equipment. Events that contribute to the occurrence of a fire are considered. The most characteristic factors that cause the ignition of electrical elements of the electric heating equipment system are listed. A tree of events leading to the fire occurrence in such systems is presented. Specific features are noted concerning thermal processes in the electrical part of the equipment associated with the possibility of ignition in the electrical elements. Analytical expressions for determining the probability of fire and its components are given. Calculation is based on the reliability indicators of the system and devices elements for protective shutdown of the circuits with fire hazardous modes. The possibility is shown related to practical application of the above methodology for assessing fire risk in the equipment with electric heaters. This methodology also allows to justify the need or sufficiency of fire-fighting technical solutions.