PTC서미스터 히터소자를 적용시킨 전기온풍기의 발화 매커니즘 연구

Abstract

Electric heaters with PTC thermistor heater elements have been widely used for heating at home and businesses, replacing heating devices using fossil fuels. The PTC thermistor heater device maintains a constant temperature by controlling a heating value by increasing or decreasing the current as the resistance value changes to limit the amount of current. In this paper, since a fire occurs due to indiscreet use of the device, careless use of the PTC thermistor heater device-type electric heater and the defect state of the device itself were presented. After that, the heating characteristics and the possibility of firing were analyzed through lots of experiments. As the separation distance from the combustible material approached, the temperature of the combustibles material increased proportionally. However, the temperature of the PTC thermistor heater element itself was kept constant. In addition, even if serious overheating conditions were set, the temperature overheating prevention device of the device itself was operated, which did not lead to abnormal overheating and firing of the heater device itself. It could be verified through empirical experiments that the firing could be caused by arc generation between PTC heater device and adjacent electrode, as an abnormal current occurs under conditions where the resistance of thermistor itself is interfered with by the inflow of external conductive materials. In conclusion, based on the results of the reproduction test, matters to be considered when improving the fire investigation and fire prevention system were presented.