矿井10MHz以下通信射频设备安全距离的研究

Safe distance for telecommunication radiofrequency transmitter with frequency below 10 MHz in underground mines

建立了工作频率在10 MHz范围内的煤矿井下射频设备与雷管间安全距离的计算模型,将雷管脚线视为回路天线,得出了雷管脚线的内阻抗、回路线的互感系数以及外电感系数的计算公式,和流经回路线上的总电流公式,建立了射频设备与雷管间安全距离的计算公式。基于该模型,分析了射频发射设备的工作频率和雷管脚线面积变化对安全距离的影响。结果表明:煤矿井下射频设备与雷管之间的本安距离为3 m,即只要相距大于3 m,工作频率在10 MHz以下的射频设备,其辐射能量就不会对雷管构成安全隐患。

The computing model of safe distance between detonator and radiofrequency transmitter working at the frequency band below 10 MHz in coal mines was established.The detonator pin was considered as a loop antenna.Based on that,obtained the calculation formula of the internal resistance of detonator pin,the mutual and the external inductance of the loop line,and then the total current formula in the loop line was obtained,the calculation formula of safe distance between RF transmitter and detonator was deduced at the end.Two influences on safe distance in the model were analyzed,which were caused by the area of detonator pin and working frequency of RF transmitter.The results show that the safe distance between RF transmitter and detonator in underground mines is 3 meters.In other words,as long as the distance is over 3 meters,the radiation energy of transmitter with frequency below 10 MHz,will not be a threat to detonator.