Introduction of common heating elements in heating board industry
In the current heating board industry, there are many types of heating elements, and their functions and characteristics are different. Next, I will briefly introduce four different heating elements, among which:
1. Heating wire: heating wire is a kind of heating element that appeared early in zui and USES heating as the basic working principle to realize energy conversion. Although heating wire is a traditional heating element, it has not been replaced yet and is still widely used in various fields, especially in industrial production and laboratory. Most electric heating wires are made of ferrochrome aluminum alloy and nickel-chromium alloy. The high temperature of ferrochrome aluminum alloy zui has reached 1400℃. In recent years, electric heating elements such as electric heating rod, electric heating plate and electric heating sheet have been developed on the basis of electric heating wire. The advantages of electric heating board are high heating temperature and heat resistance temperature, mature technology, easy to manufacture and convenient to be used in various electric heating equipment. The disadvantage of the heating wire is that its energy conversion rate is low. The heating process is accompanied by the luminescence process, so the energy conversion rate can only reach 60 to 70 percent.
2. Electrothermal film: electrothermal film is an emerging heating element in recent years, which is made by absorbing the characteristics of PTC and conductive coating. At present, it is mainly used in indoor heating and environmental temperature maintenance, such as building heating, incubation room insulation and so on. The advantages are no flame heating, surface heating, less thermal resistance, fast heat conduction, long service life, and easy to cut and separate, especially the electrical energy conversion efficiency of electric film up to 90%, small heat loss. The disadvantage of the electrothermal film is that the heating rate is slow, the heating temperature cannot reach a high value, the heat dissipation speed after power failure.
3. PTC heating element: PTC, also known as thermistor, is a kind of heating element made of composite sintering of conductive materials. PTC heating element is a kind of heating element after heating wire. Limited by Curie temperature, it can only be used in heating below 350℃, and it is applied to various low-temperature heating equipment with low power. The advantage of PTC heating element is that there is no flame when heating and the heating efficiency is up to 70%. The disadvantage of PTC heating element is that it has poor seismic performance and cannot be cut and used at will. In particular, PTC heating element is limited by Curie temperature and cannot be used for heating above 350℃. Therefore, the application of PTC heating element in practical production and life can only be limited to low-temperature heating field.
4. Conductive coating: conductive coating, also known as black film, was produced in the late 1950s and can be used as heating element after being sprayed on the surface of insulation material. Conductive coating itself has many USES, but it is seldom used as heating element. Its advantages are planar heating, large heat dissipation area and good seismic performance, but its disadvantages are that the heating layer is easy to fall off, and it can only be applied to heating below 200℃.