HAZARDOUS SUBSTANCES IN ATMOSPHERIC DISCHARGES OF PIPE FURNACES REFINING PLANTS

The article deals with atmospheric emissions from fuel combustion in tubular furnaces of oil refineries

GROUNDING METHODOLOGY IN A 550 kV AC POWER TRANSMISSION LINE IN THE AMAZON - A CASE STUDY

Atmospheric discharges are indispensable for the electrical sector due to their responsibility on the shutdown of the power lines, what may trigger a sequence of events that led the interconnected electrical system to collapse. The aim of this case study is to demonstrate the development of a viable methodology in order to reduce the resistance values of the grounding system of the power lines, reducing shutdown occurrences due to returning disruptive discharges, or backflashover, mitigating the damages caused to the electrical system and to society, in order to improve the quality of the electrical power distribution. Considering the factors of implementation costs, technical environmental viability, the encompassment of this solution for other structures lines, and the reduction of the implementation percentage, it was concluded that the most adequate solution to implement a more robust grounding system in the transmission power lines is the solution 03 tested on the tower 585, with a reduction of 66,98%.

Spatial analysis of atmospheric discharges in Lubelszczyzna in 2018

The aim of the study was to analyse lightning discharges over the Lublin region in 2018 using GIS tools. The methods and systems for detection and location of lightning discharges were presented. The impact of terrain coverage, height above sea level, and location of transceiver stations of mobile operators on the occurrence of discharges was shown. The study provides knowledge of theoretically safer areas and those particularly vulnerable to lightning strikes. Additionally, statistics related to lightning discharges over the Lublin region in 2018 were presented. The analyses were carried out on vector data on the atmospheric discharges, vector data from the transceiver stations, vector data containing information on administrative units, and data from the CORINE Land Cover 2018 and on the digital elevation model. The results of the analyses confirmed that areas of airports are particularly exposed to lightning strikes, whereas beaches and sand dunes are the safest areas. It was also found that lightning strikes more often hit coniferous forests than deciduous forests. As indicated by the statistics, May is the month with the largest number of stormy days, while the largest number of lightning strikes is July.

Transient Process at Atmospheric Discharge into the Landline and the Appearance of an Electric Arc in the Switch

This document proposes a model of the process of atmospheric discharge of overhead lines followed by an electric arc. The intensity of atmospheric discharges, followed by electric arc and destruction, is determined by the difference in potential and current. Such a structure and form of discharge make it difficult to analyze the transient process and obtain adequate solutions. That is why the model of the transient process in the electric arc of the switch under the conditions of interruption of the AC circuit is specially analyzed. Simple equivalent schemes for the analysis of phenomena with given values of linear parameters are presented, which are very simple to apply. All influential parameters by which the overvoltage values in the model can be estimated were also taken into account. The evaluation of the proposed model was performed using the adapted MATLAB program psbsurlightcuurent for atmospheric electrical discharge, which contains a high frequency current source. The verified simulation method was used to verify the results as part of a method derived from artificial intelligence algorithms. The process simulation program, the obtained voltage and current diagrams confirm the application of the simulation algorithm model.

Mesoscale convective systems as a source of electromagnetic signals registered by ground-based system and DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) satellite

Mesoscale convective systems (MCSs) are especially visible in the summertime when there is an advection of warm maritime air from the west. Advection of air masses is enriched by water vapour, the source of which can be found over the Mediterranean Sea. In propitious atmospheric conditions, and thus significant convection, atmospheric instability or strong vertical thermal gradient leads to the development of strong thunderstorm systems. In this paper, we discuss one case of MCSs, which generated a significant amount of +CG (cloud-to-ground), −CG and intracloud (IC) discharges. We have focused on the ELF (extremely low frequency; < 1 kHz) electromagnetic field measurements, since they allow us to compute the charge moments of atmospheric discharges. Identification of the MCSs is a complex process, due to many variables which have to be taken into account. For our research, we took into consideration a few tools, such as cloud reflectivity, atmospheric soundings and data provided by PERUN (Polish system of the discharge localisation system), which operates in a very high frequency (VHF) range (113.5–114.5 MHz). Combining the above-described measurement systems and tools, we identified a MCS which occurred in Poland on 23 July 2009. Furthermore, it fulfilled our requirements since the thunderstorm crossed the path of the DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) overpass.

Spatial Diversity of Cloud-to-Ground Lightning Flashes in the Kujawsko-Pomorskie Voivodeship (Poland), 2002-2019

This research focuses on the spatial diversity of cloud-to-ground (CG) flashes in the Kujawsko-Pomorskie voivodeship (Poland) based on data from the PERUN lightning detection system, 2002-2019. The storm season usually lasts from May to September, with July having the highest number of thunderstorms days and flashes. Thunderstorms most often occur in the afternoon. A generated grid of 5×5-km cells was used to characterise the variables related to CG flashes. In the analysed period 432,925 CG flashes were detected in the voivodeship (24,051 flashes year-1). The highest electrical activity was found in the south-eastern part of the province. In grids with a large water surface, the number of CG flashes was small and increased with distance from the Vistula River. The distribution of atmospheric discharges in major cities of the region (Bydgoszcz, Toruń, Włocławek and Grudziądz) was random. Years with greater electrical storm activity (27,614 discharges in 2017) are interspersed with calmer years (5000-7000 discharges). There were found an upward trend in lightning discharges (of 1681 discharges year-1) during period 2002-2019. To develop maps specifying the number of thunderstorm days, a 1×1-km grid cell was used with a 15-km radius buffer from the bin centre. The annual number of thunderstorm days in the voivodeship fluctuates from 27 to 41 days and increases from north-west to south-east. Consecutive days with a thunderstorm, the most common runs are of three days in a row with a storm. The number of thunderstorm days shows an increasing trend (0.82 days year-1). This trend is related to the increase in air temperature in the storm season (Apr-Sept) reaching (0.04°C/year).

Simulation of Atmospheric Discharge at Power Line

Modelling electrical circuits by application of schemes containing elements with distributed parameters such as transmission lines has been applied in this research. Functions approximating voltage or current atmospheric discharges have been presented together with frequency spectra of these functions. The results of computer simulations obtained with the help of PSpice software have been presented for a simplified three-phase circuit subject to such discharge.