PTC thermistor constant temperature heating characteristic design adopts PTC ceramic heating components composed of special ceramic materials. Due to the incomparable advantages of traditional heating components such as constant temperature heating, no open flame, high heat conversion rate, long life, safety and environmental protection, more and more It is widely used in various household appliances, including liquid heaters. At present, liquid heaters, such as electric stew pots and water-proof electric stew pots of kitchen appliances, mainly use PTC heaters to heat the bottom surface of the inner pot, or use water as a medium to heat the food in the inner pot. The PTC heater used for liquid heaters usually includes an aluminum frame and a PTC heating element. The aluminum frame includes an aluminum heating plate and a heating element positioning sleeve set on the bottom surface of the aluminum heating plate. The PTC heating element is inserted into the heating element positioning sleeve in. However, with this structure, the surface of the aluminum heating plate is prone to blackening due to oxidation after being used for a period of time, which is unfavorable to the heat transfer of the PTC heater, and easily leads to uneven heat distribution, resulting in different areas in the inner pot. Foods get different calories. Some foods get more calories, and some foods get less calories, which affects the cooking effect; and for PTC heaters that directly heat water, there are hidden product quality problems because the aluminum heating plate is easily corroded and damaged. The appearance of oxidized blackening on the outer surface of the rack improves the heat transfer performance of the aluminum heating plate at variable, keeps the temperature consistent throughout the aluminum heating plate, reduces the energy consumption, and increases the number of PTC heating parts.
Moreover, each PTC heating element is evenly distributed on the underside of the aluminum heating plate, which makes the input power initiation rate more stable and enables the aluminum heating plate to be heated more uniformly, making it easier to maintain the same temperature throughout the aluminum heating or preheating plate, thus improving the application effect.