The calculation of the regulated number of remote sensors of gas analyzers surrounding rectangular outdoor facilities at oil refineries

Introduction. The authors emphasize the importance of pre-explosive concentration sensors, that ensure the required fire safety (FS) at fire/explosion hazardous facilities of oil refineries. The authors substantiate the importance of maintenance procedures for first-level alarming devices that are part of automated process control systems (APCS) installed around outdoor facilities of refineries. Theoretical fundamentals. The authors argue that two counter-running subprocesses (destructive and creative (restorative)), that ensure fire safety, can describe a decrease in the efficiency of APCS subsystems in the FS monitoring, as well as their restoration at refinery facilities. The proper maintenance of gas detectors is presented as a discrete creative subprocess. The authors demonstrate a relation between the spatial location of sensors of stationary gas analyzers and the computability of their number, depending on the outdoor facility perimeter. Research results. To mathematically describe the maintenance procedure applied to stationary gas analyzers, the authors assess the dependence between the number of remote detectors, the perimeter of the rectangular outdoor unit, around which they are installed at a refinery, and the prescribed distance between the sensors. Conclusion. This assessment conveys the features of installation of gas detectors of any type depending on their classification based on physical methods of analysis. A conclusion is drawn that the perimeter data can help to calculate the number of rows for the installation of devices, the length of each row, the prescribed number of gas detectors in each row.