Numerical assessment of passive fire protection in an oil and gas storage facility

Oil storage and processing facilities, such as refineries, are constantly handling large quantities of hydrocarbons and chemicals in both liquid and gas forms that are inherently flammable. If accidents or errors such as human mistakes, equipment failure or deficiency in management plan were to occur, there is a high risk that property loss, economic disruption and production interruption will occur (Baalisampang et al. 2018a). To tackle such issues, there are a variety of guidelines and standards for refinery construction, building material selection and layout design to prevent accidents from occurring and to reduce the impact of structural, economical and production accidents. However, although guidelines and standards are constantly being updated and implemented, it is observed that chance of fires, detonations and explosions occurring cannot be eliminated in the hydrocarbon processing industry as too much flammable hydrocarbon is being handled (Vervalin 1985), and there are countless modes of failure in this industry (Baalisampang et al. 2018b). According to Chang and Lin (2006), of the type of complex in which fire and explosion have occurred over the past 50 years, 116 of 242 accidents occurred in refineries which contribute to approximately 50% of the accidents. Among the 116 accidents in refineries, 60% of them are related to fire. In addition, Hu et al. (2013) concluded that 27% of major accidents over the past 30 years occurred in petroleum refineries and fire or explosion accounted for 96% of the total number of cases. Based on these researches, it is observed that fire protection systems that are commonly installed in hydrocarbon storage facilities must be considered and selected carefully. This has not been extensively studied previously. Fire protection system (FPS) is designed to respond to fire if fire or smoke is detected, and it can be categorised into an active, passive, and inherent fire protection system (Baalisampang et al. 2016). Active fire protection (AFP) is a system or component that requires human action or some mechanisms to activate and is employed to suppress and mitigate the fire. On the other hand, passive fire protection (PFP) system is a defensive mechanism that requires no activation method to prevent the spread of fire and disintegration of structure (Roe 2000). Some examples of PFP are fire rated walls and doors, fire protection spray and self-expanding foam which are designed to limit the temperature rise and excessive heat absorption of equipment and structures. Another type of PFP system is intended to prevent the spread of hydrocarbon particularly liquid hydrocarbon which includes drainage sumps and bunds (Spitzenberger et al. 2016). With such a wide variety of fire protection systems, the choice of an FPS is mainly dependent on the targeted fire type, i.e. pool fire, jet fire or flash fire. A selection of an FPS must be considered carefully to maximise the effectiveness of the PFP applied. In addition, immoderate or excessive use of PFP can lead to problems such as increase in fabrication and building cost, risk of schedule delay (Friebe et al. 2014) and increased difficulty in performing corrosion testing (Tugnoli et al. 2012). Thus, selection of the PFP system and careful consideration of the combination of passive and active fire protection systems are of great importance.