Oxidative heat release intensity in coal at low temperatures measured by the hot-wire method

Directly measuring the oxidative heat release intensity at low temperatures is difficult at present. We developed a new method based on heat conduction theory that directly measures heat release intensity of loose coal at low temperatures. Using this method, we calculated the oxidative heat release intensity of differently sized loose coals by comparing the temperature rise of the coal in nitrogen or an air environment. The results show that oxidation heat release intensity of Shenhua coal sized 0∼15 mm is 0.001∼0.03 W/m3 at 30∼90 °C and increases with increasing temperature. The heat release intensity at a given temperature is larger for smaller sized coal. The temperature effect on heat release intensity is muted as the coal size increases. At lower temperature the change in heat release intensity as a function of size becomes smaller. These results show that the test system is usable for practical applications and is easy to operate and is capable of measuring mass samples.