Evaluation of the dust potential hazard of thermal power plants through coal dust combustion and explosion characteristics

Abstract

Thermal power is the main source of electricity in Taiwan, where coal is the primary fuel. However, concerns for potential fire and explosion hazards caused by coal dust are increasing. The problem regarding the storage or transportation process of coal cannot be neglected. This study explored four coal dust samples obtained from the three regions of South Africa, Russia, and Australia; the particle size D50 of all the samples was < 75 μm. The intrinsic safety characteristics of combustion and explosion in coal dust were studied using the minimum ignition energy (MIE) test, minimum ignition temperature (MIT) of cloud apparatus, and 20-L apparatus. Russian coal exhibited the lowest MIE and MIT values of 550 °C and 120 mJ, respectively. Furthermore, the minimum dust explosion concentration was 30 g m−3 in Australian coal. These experimental results, combined with the on-site investigation, indicated that appropriate countermeasures are sufficient to reduce dust hazards. The results showed that the dust explosion risk of a properly operating thermal power plant is considerably low.