Research on safety of electromagnetic wave thermal effect in explosive environment of underground coal mine

GB/T 3836.1-2021 Explosive atmospheres-Part 1: Equipment-General requirements stipulates that the threshold power of RF equipment in explosive environments shall not exceed 6 W. This regulation limits the application of high-power RF equipment in coal mines. However, existing research on electromagnetic safety in explosive environments lacks comprehensive theoretical analysis and experimental verification. In order to solve the above problems, the electromagnetic wave thermal effect equation is derived. It is analyzed that the controllable parameters affecting the generation of thermal energy from the mixture of gas and coal dust coupled by electromagnetic waves are the electromagnetic wave coupling time, the electric field strength and the electromagnetic wave frequency. Based on the regulation in GB/T 3836.1-2021 that the maximum surface temperature of electrical equipment that may accumulate coal dust cannot exceed 150 ℃, simulation experiments are conducted using the multi physics field simulation softwar