The convection type internal heater structure is mainly composed of a housing, a heat dissipation plate, an air convection air intake grille, an air convection outflow air grille, a control element, and the like. Among them, the tubular electric heating tube is used as the electric heating element of the heat dissipation switch. The heat transfer through the heat sink and the air outlet grill of the heater metal table is the most, GB 4706.23-2007 "Safety of household and similar electrical appliances Part 2: Special requirements for indoor heaters" standard requirements (Table 1) : For portable and non-high-mounted non-fan heaters, the metal is cut into a fFJ air outlet grid and the surrounding surface temperature rise should not exceed 130K, and the other surface temperatures touched by the test rod must not exceed 85K.
When the indoor heater is not equipped with temperature control components, it operates at 1.15 times the rated input power under normal working conditions according to the standard requirements. The thermocouple method is used to measure the temperature rise of the appliance. Point), the center of the outlet grid (point B), the top can touch the center of the surface (point c), the front surface of the heater can touch the bottom of the center of the surface (point D) temperature rise curve.
According to the results, after the indoor heater works stably, the temperature of position A is 130 degree, which exceeds the safety standard requirements (21.6 ℃ + 85K). It is necessary to install a suitable temperature control element in the indoor heater for control. The temperature at position A is the highest, and it will be used as a point that can reflect the maximum heating effect of the indoor heater in the subsequent tests.
