Application of the ALOHA simulation model to assess Ammonia leakage from the coal-fired power station of Duyen Hai 2 Thermal Power Plant

Abstract

The widespread use of hazardous chemicals in industrial activities can cause chemical accidents in which Ammonia gas leaks are one of the most concerning issues due to their toxic nature and adverse impacts on workers and the working environment. Therefore, accident risk prediction is essential to reduce the extent of damage and develop plans in place for minimizing and controlling unexpected hazards. This paper aims to provide an estimation of Ammonia leakage by ALOHA simulation software with scenarios for Ammonia leakage escaping from storage tanks of a coal-fired power station at Duyen Hai 2 Thermal Power Plant, Tra Vinh province. Three scenarios of chemical (Ammonia) incidents were simulated to assess the degree and extent of the impacts of chemical leakage on humans and the environments, including monthly, seasonally scenarios (for single chemical tank incidents) and two-tank incident scenario. The results show that the monthly scenario in April (29°C; 80,4%; 3,4m/s) and November (27,14°C; 87,2%; 2,9m/s) have the largest influence and the worst effects with the radius of red zone damage of 3.3km from the leakage site. The scenario of the dry season has much higher damage than the rainy one with the red zone is 4.6km. Meanwhile, the damage area of red zone caused by chemical incidents from two tanks leakage is 5.3km. This finding provide the top management level of the factory with a critical view of damage extent caused by chemical incidents for which a proactive plan should be available to prevent from the risks of explosion.