Experimental Study on the Abnormal Potential Distribution Around the Heat Source of Spontaneous Combustion of Coal

If a temperature gradient is maintained across a porous medium like an aggregation of broken rocks, a corresponding voltage gradient will appear across it. It is possible, in principle, to measure this potential. Therefore, in this study model experiments were performed to investigate whether the potential distribution created by heat in the medium can be detected. According to the experimental results, the abnormal potential around the heat source has been detected in all the experiments irrespective of the intensity of the heat source and the heating time. The results also show that it is possible to locate the heat source by the measurement of the potential distribution, because the distribution of abnormal potential greatly depends on the position of the heat source.