Simulation on Temperature Uniformity of Resistance Heating Elements

Aiming at the prevalent problem of uneven heating temperature distribution of resistance heating elements, the electro-thermal coupling simulation method was employed to study and optimize the structure and materials of heating elements in order to reduce the temperature difference in varied areas. The temperature uniformity coefficient was adopted as a quantitative index for the temperature uniformity of the heating element. Firstly, the influence of the bending structure parameters, such as the bending gap width, inner chamfer and outer chamfer of the heating elements, on the uniformity of temperature distribution were investigated. As a result, on the basis of the original heating element, an optimized design of a heating element structure that can achieve the best temperature uniformity is accomplished. This structure mainly adopts a bending configuration that combines an inner fillet with a radius of R₁= 0.3 mm and an outer right angle, with a gap width of 0.5 mm. Eventually, the effect of different PTC materials on the temperature uniformity is further investigated, including aluminum-copper alloy, copper-nickel alloy, nickel-chromium alloy. It was found that the aluminum-copper alloy material with higher resistivity and higher thermal conductivity helps to improve the temperature uniformity of the heating elements. Especially under relatively high voltages (ranging from 3.0 V to 4.5 V), the aluminum-copper alloy exhibits good temperature uniformity, which has certain reference significance for practical design and application.