Påvirkningen af fordelingen af varmetråden på varmerørets temperatur
Whether the surface temperature of the electric heating tube is uniform or not is an important technical indicator to measure the quality of the electric heating tube, which will directly affect the actual use effect, life and safety of the electric heating tube. The main reason for the temperature difference on the surface of the electric heating tube is the uneven density and eccentricity inside the electric heating tube, which eventually leads to the uneven temperature.
① Uneven density means that the heating wires are arranged closely in one section of the electric heating tube, and the other section is arranged in a loose or even straight line. At this time, the electric heating tube will have serious temperature unevenness. If the heating wires in the tube are not uniformly arranged, the number of helical turns of the heating wire per unit length will be many. Conversely, the power per unit length is small.
The surface load is the power per unit area on the heating surface, and as the local power increases, the local surface load also increases accordingly. The surface load is closely related to the surface temperature. When the surface load increases, the surface temperature of the electric heating tube increases, and when the surface load decreases, the surface temperature of the electric heating tube decreases.
② The so-called eccentricity means that the central axis of the spiral heating wire deviates from the central axis of the heating tube, so that the heating wire is too close to the wall of the heating tube on one side, and has a larger distance from the other side. Considering the heat conduction of the heat transfer medium The coefficient and the thickness of the heat transfer medium on both sides are inconsistent, resulting in uneven temperature on the surface of the tube.